Relevant bibliographies by topics / Surface normale

Academic literature on the topic 'Surface normale'

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Published: 28 February 2024

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Journal articles on the topic "Surface normale"

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Vaquie, M. "surface normale." Duke Mathematical Journal 57, no. 1 (August 1988): 69–84. http://dx.doi.org/10.1215/s0012-7094-88-05703-1.

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Snoussi, J. "Limites d'espaces tangents � une surface normale." Commentarii Mathematici Helvetici 76, no. 1 (March 1, 2001): 61–88. http://dx.doi.org/10.1007/s000140050150.

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Snoussi, Jawad. "Limites d’espaces tangents à une surface normale." Comptes Rendus de l'Académie des Sciences - Series I - Mathematics 327, no. 4 (August 1998): 369–72. http://dx.doi.org/10.1016/s0764-4442(99)80050-0.

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Vaquié, Michel. "Résolution simultanée d'une famille de singularités rationnelles de surface normale." Annales de l’institut Fourier 35, no. 4 (1985): 1–37. http://dx.doi.org/10.5802/aif.1026.

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Gallucci, M., O. Gagliardo, A. Splendiani, and R. De Amicis. "La loggia cavernosa: Anatomia neuroradiologica normale." Rivista di Neuroradiologia 13, no. 3 (June 2000): 367–73. http://dx.doi.org/10.1177/197140090001300307.

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Il termine “loggia cavernosa”, sinonimo di “regione parasellare” indica l'insieme di strutture latero-sellari, differenziabili embriologicamente in almeno tre comparti: il seno cavernoso propriamente detto, di origine vascolare, la regione dell'apice orbitario, di derivazione orbitaria, e, infine, la regione del cavo di Meckel, di derivazione pterigo-mascellare. Viene riportata una revisione di anatomia normale ottenuta in vivo con tecniche di moderna neuroradiologia, per lo più derivate da ricostruzioni tridimensionali con algoritmi Shaded Surface Display (SSD) di acquisizioni TC, ottenute con tecnica elicoidale, e RM con sequenze 3D.
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FEVERY J, VANFLETEREN L, DOCKX S, PEREZ-GUTIERREZ N, and NEVENS F. "Hoe inactief is de leverziekte bij hepatitis B-"surface"-antigeenpositieve patiënten met normale transaminasen?" Tijdschrift voor Geneeskunde 63, no. 12 (January 1, 2007): 549–55. http://dx.doi.org/10.2143/tvg.63.12.2000102.

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CEUPPENS W, FEVERY J, and NEVENS F. "Hoe inactief is de leverziekte bij hepatitis B-"surface"-antigeenpositieve patiënten met normale transaminasen?" Tijdschrift voor Geneeskunde 63, no. 23 (January 1, 2007): 1207. http://dx.doi.org/10.2143/tvg.63.23.2000218.

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CEUPPENS W, FEVERY J, and NEVENS F. "Hoe inactief is de leverziekte bij hepatitis B-"surface"-antigeenpositieve patiënten met normale transaminasen?" Tijdschrift voor Geneeskunde, no. 23 (January 1, 2007): 1207. http://dx.doi.org/10.47671/tvg.63.23.2000218.

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FEVERY J, VANFLETEREN L, DOCKX S, PEREZ-GUTIERREZ N, and NEVENS F. "Hoe inactief is de leverziekte bij hepatitis B-"surface"-antigeenpositieve patiënten met normale transaminasen?" Tijdschrift voor Geneeskunde, no. 12 (January 1, 2007): 549–55. http://dx.doi.org/10.47671/tvg.63.12.2000102.

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D’Almeida, Jean. "Surfaces associées au plongement canonique des courbes." Nagoya Mathematical Journal 140 (December 1995): 33–39. http://dx.doi.org/10.1017/s0027763000005407.

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Soit C une courbe canonique de genre g ≥ 4. Le théorème de Enriques-Babbage [ACGH] affirme que l’idéal de C est engendré par (g − 2) (g − 3)/2 hypersurfaces quadriques sauf si C est trigonale ou isomorphe à une quintique plane. Si C est trigonale, elle est tracée sur une surface réglée rationnelle normale dont les génératrices découpent la série trigonale. Si C est isomorphe à une quintique plane lisse, elle est tracée sur une surface de Veronése.
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Dissertations / Theses on the topic "Surface normale"

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Snoussi, Jawad. "Limites d'espaces tangents à une surface normale." Aix-Marseille 1, 1998. http://www.theses.fr/1998AIX11037.

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Dans ce travail, nous donnons des caracterisations numeriques et geometriques de l'ensemble des limites d'hyperplans tangents a un germe de surface normale (s,0) plongee dans c n. Nous demontrons qu'un hyperplan h n'est pas une limite d'hyperplans tangents a s en 0 si et seulement si la section de h avec s est reduite et son nombre de milnor est minimum parmi ceux des sections hyperplanes reduites. Il est connu que l'ensemble des limites d'hyperplans tangents a la surface s en 0 est la reunion de l'ensemble des hyperplans tangents au cone tangent de s en 0 et de l'ensemble des hyperplans contenant des generatrices particulieres du cone dites tangentes exceptionnelles de s en 0. On sait egalement que ces tangentes exceptionnelles correspondent aux points fixes du systeme lineaire des courbes polaires par l'eclatement de l'origine dans s. Nous prouvons ici que les tangentes exceptionnelles de s en 0 correspondent aux points ou la famille des sections hyperplanes de s n'admet pas de resolution simultanee faible, ce qui nous permet de les determiner precisement sur le diviseur exceptionnel de l'eclatement de l'origine. En etendant la notion de composantes de tyurina a une desingularisation raisonnable d'une surface normale, nous demontrons que ces composantes se contractent sur des points fixes du systeme lineaire des courbes polaires par l'eclatement de l'origine. En appliquant ces techniques a l'etude des pinceaux de courbes sur un germe de surface normale, nous determinons les valeurs dites speciales d'un pinceau de courbe, c'est a dire celles pour lesquelles la topologie de la courbe n'est pas generique.
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Roman, Adriana. "Méthodes d'indentation normale et transverse appliquées à l'étude des propriétés mécaniques des films et révêtements." Lille 1, 2000. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2000/50376-2000-276.pdf.

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Le travail presente dans ce memoire entre dans le cadre du developpement des activites du laboratoire dediees a la determination par indentation de la durete des materiaux. La premiere partie du document est consacree a l'etude de revetements de nickel-phosphore obtenus industriellement et etudies ici dans deux etats de traitements thermiques de recuit a 300\c et 600\c. Pour ces deux modalites il a ete possible de determiner la tenacite des revetements a partir de l'observation des fissures de type palmqvist, generees par indentation vickers normale. Dans la seconde partie l'effort est porte sur la determination de la durete de films de diamant en comparant les resultats obtenus a partir de quelques modeles parmi les plus utilises. Ces modeles decrivent la durete composite superficielle en fonction de la durete du film et du substrat. Enfin, en cherchant a s'affranchir de la connaissance du module d'elasticite du film necessaire dans le modele de chicot et lesage, on propose un nouveau modele de description de la durete composite permettant de prendre en compte la transition de comportement de type substrat ou de type film en fonction de la profondeur relative d'indentation.
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Maritaud, Karl. "Rendu réaliste d'arbres vus de près en images de synthèse." Limoges, 2003. http://aurore.unilim.fr/theses/nxfile/default/26d2f3b6-ee12-4232-956d-706abdfbda53/blobholder:0/2003LIMO0049.pdf.

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La plupart des travaux pour représenter des arbres en Infographie se sont orientés sur des méthodes conçues pour des points de vue éloignés où les détails de l'écorce et des feuilles ne sont pas perceptibles. Le rendu réaliste d'arbres vus de près reste un problème ouvert et difficile, essentiellement à cause de la complexité visuelle de l'écorce. Ici, des méthodes basées-image sont proposées pour extraire le relief et la couleur d'une texture réelle d'écorce à partir d'une simple photographie, sans manipulation compliquée, et ensuite pour synthétiser des textures 3D d'écorces réalistes. Une méthode est proposée pour appliquer ces textures, sans répétition ni discontinuité, sur des branches modélisées par déplacement de surfaces implicites mélangées sans gonflement. D'autre part, une technique est proposée pour extraire le relief des nervures des feuilles. Ensemble, ces méthodes nous permettent d'obtenir un haut niveau de réalisme visuel pour représenter des arbres vus de près
Most of the research in the rendering of trees in Computer Graphics has focused on methods designed for viewpoints at a certain distance where the details of the bark and leaves are not perceptible. Rendering realistic trees at a short distance remains an open and difficult problem, essentially due to the visual complexity of bark textures. Here, image-based methods are proposed to extract the relief and color from a single photograph of real bark texture, without any complicated manipulations, and then to automatically synthesize realistic 3D bark textures. A method is proposed to apply these textures, with neither repetition nor discontinuities on the texture, onto branches modeled by displacement-mapped implicit surfaces, which are blended without bulge. Moreover, a technique for extracting the relief of leaf veins is proposed. Together, these methods allow us to achieve a high degree of visual realism for rendering close-up views of trees
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Margirier, Audrey. "Tectonique et processus d’exhumation des Cordillères Blanche et Noire en contexte de subduction horizontale (Nord Pérou)." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAU023/document.

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Ma thèse se focalise sur l'étude des mécanismes qui ont conduit au soulèvement et à la construction du relief dans les Andes du Nord du Pérou. Dans cette région, la Cordillère Blanche forme les plus hauts sommets péruviens (> 6000 m) et constitue une anomalie à l'échelle des Andes. La morphologie de cette région des Andes est marquée par un pluton de forme atypique, allongé et à l'affleurement sur plus de 150 km. Ce pluton est bordé par une faille normale de plus de 200 km de long. La présence de cette faille normale majeure en contexte de subduction plane reste surprenante car ces zones de subduction planes semblent induire une augmentation du raccourcissement dans la plaque chevauchante. Mon travail a eu pour objectifs de caractériser les variations de l'état de contraintes régional, l'âge du soulèvement et de discuter les processus géodynamiques qui ont contribué à la formation du relief. Dans ce cadre, j'ai utilisé une approche pluridisciplinaire impliquant sur plusieurs échelles spatio-temporelles et comprenant à la fois de nouvelles données de terrain, leur analyse et leur modélisation.Mes données de microtectonique indiquent qu'il est possible de générer de l'extension au dessus d'une subduction plane à l'échelle régionale. Ces données sont en contradiction avec l'augmentation du raccourcissement classiquement attendue dans la plaque chevauchante. Mes nouvelles données de thermochronologie basse température et leur modélisation montrent une augmentation de l'exhumation induite par le soulèvement de la Cordillère Occidentale à 15 Ma. En les confrontant aux modèles précédents, je propose un soulèvement régional lié à l'aplatissement de la subduction et à la topographie dynamique associée.J'ai également étudié l'impact de l'arc Miocène sur le soulèvement à une échelle plus locale. Pour cela, j'ai compilé tous les âges de refroidissement du pluton disponibles dans la littérature. En parallèle, j'ai obtenu les premières données de profondeur de mise en place du batholite de la Cordillère Blanche. Cela m'a permis de proposer une structure du batholite en sills empilés puis basculés vers l'est. De plus, la modélisation des variations spatio-temporelle des taux d'érosion à partir des données de thermochronologie basse température indique une augmentation importante des taux d'érosion dans la Cordillère Blanche à partir de 2 Ma. L'arc Miocène ne semble donc pas contribuer significativement au soulèvement malgré sa probable contribution à l'épaississement de la lithosphère. En revanche, l'érosion glaciaire récente semble contribuer fortement à l'exhumation de la Cordillère Blanche et au basculement du batholite.Dans la dernière partie de ma thèse, pour quantifier l'importance de l'érosion dans la création du relief et le soulèvement, j'ai modélisé l'évolution du paysage de la région (FastScape). Mes modélisations numériques démontrent le rôle majeur de l'érosion et du rebond flexural associé dans la création du relief et les taux de soulèvement. Pour finir, basée sur les données de la littérature et celles apportées par mon travail de thèse, je propose un nouveau modèle pour expliquer la faille normale de la Cordillère Blanche dans son contexte régional. Ce modèle implique une faille normale d'extrado et l'érosion importante du mur de la faille
My thesis focuses on the mechanisms that controlled the uplift and construction of the relief in the northern Peruvian Andes. In this area, the Cordillera Blanca forms the highest peaks in Peru (> 6000 m), which is a topographic anomaly across the Andes. The morphology of the Cordillera Blanca is marked by an elongated pluton, which outcrops over 150 km. In addition, this pluton is bordered by the largest normal fault from South America. The presence of this major normal fault in a flat-slab context remains surprising because flat slabs usually induce an increase of the shortening in the overriding plate. The aim of my work is to characterize the variations of the regional stress field, the age of the uplift and discuss the geodynamic processes that contributed to relief building. To address these issues, I used a multidisciplinary approach involving new field data, their analysis and modeling.My microtectonic dataset reveals regional extension above the Peruvian flat-slab. This data contradicts the expected increase of shortening in the overriding plate. Modeling my new thermochronologic data shows an increase in the exhumation rates induced by the uplift of the Cordillera Occidental since 15 Ma. I propose that the regional uplift relates to the flattening of the subduction and associated dynamic topography.To address the impact of the Miocene arc on the uplift at a more local scale, I compiled the cooling ages of the pluton available in the literature. In parallel, I obtained the first amphibole thermo-barometry data that constrains emplacement depth of the Cordillera Blanca batholith. Following these data, I propose that the batholith is structured in eastward-tilted sills. In addition, modeling of the space and time variations of erosion rates based on the inversion of thermochronologic data indicates that erosion rates significantly increased in the Cordillera Blanca since 2 Ma. The Miocene arc seems to insignificantly contribute to the local uplift despite its contribution to the thickening of the lithosphere. Thus, I suggest that the recent glacial erosion contributes to the exhumation of the Cordillera Blanca and subsequent tilting of the batholith.Then, I modeled the landscape evolution for the Cordillera Blanca region to quantify the contribution of erosion in the relief building and the uplift. My numerical models (FastScape) evidence the importance of erosion and associated flexural rebound in fostering relief building and the uplift rates.Finally, based on all available data, I propose a new regional model to explain the Cordillera Blanca normal fault. This model implies an extrado normal fault and erosion of the footwall
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Valibouse, Pierre. "Mesure des caractéristiques intrinsèques des matériaux dans l'eau, avec un tube à impédance en incidence normale." Compiègne, 1990. http://www.theses.fr/1990COMPD317.

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La discrétion acoustique prenant une part de plus en plus importante dans la lutte sous-marine, des matériaux de masquage acoustique sont utilises pour atténuer le rayonnement acoustique des sous-marins. Il s'avère donc nécessaire de connaître parfaitement les caractéristiques de ces matériaux afin d'en prévoir leur efficacité. Actuellement, les moyens acoustiques de caractérisation de ces matériaux ne permettent d'obtenir qu'une information relative globale sur le matériau, et non pas de connaître ses caractéristiques intrinsèques telle la célérité complexe des ondes. Le travail décrit dans cette thèse concerne le développement d'un système acoustique s'inspirant du principe des tubes à impédance aériens, qui permet d'accéder à la célérité complexe des ondes dans le matériau. Malgré le couplage fluide-structure induit par la présence de l'eau dans le tube, la plage d'utilisation de ce moyen d'essais se situe entre 50 et 2000 Hz. L'étude par éléments finis du comportement de l'échantillon placé dans le tube et soumis à une pression acoustique a permis de déterminer les conditions limites mécaniques devant lui être appliquées de manière à modéliser simplement son comportement (identique à celui d'une plaque de surface infinie). Les essais acoustiques ont mis en évidence les limites des méthodes classiques de mesure utilisées dans les tubes aériens pour accéder à la célérité complexe des matériaux. En modélisant le tube à impédance par un système multi-couches infini, l'identification par optimisation sur les célérités complexes du matériau et de l'eau à l'aide de la méthode du simplex, des fonctions de transfert théorique et expérimentale entre deux capteurs, permet d'obtenir le spectre de la célérité complexe du matériau des les basses fréquences. Les fonctions de transfert sont mesurées à l'aide des techniques référentielles ou sélectives « H1 ». Ce moyen d'essais permet aussi l'étude du comportement des matériaux soumis à une pression hydrostatique.
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Enaim, Mohammed. "Etude de la co-forgeabilité d'u multi-matériau : application à un coupe d'acier." Thesis, Paris, ENSAM, 2019. http://www.theses.fr/2019ENAM0002/document.

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Le forgeage multi-matériaux est un procédé permettant la mise en forme et l’assemblage simultanés de matériaux différents. Ce procédé permet d’obtenir des pièces multi-matériaux avec le « bon matériau placé au bon endroit ». L’objectif des travaux de thèse est de définir les conditions nécessaires à l’établissement de la liaison métallurgique par forgeage à l’interface d’un couple d’aciers. Dans un premier temps, l’état de l’art a servi à l’identification les phénomènes physiques accompagnant le forgeage multi-matériaux et les paramètres clés pilotant l’établissement de la liaison métallurgique. Le principe de base de l’établissement d’une liaison passe par la fragmentation des oxydes en surface des matériaux et par l’application d’une pression de contact favorisant le contact entre les matériaux nus et la diffusion. Les deux paramètres clés identifiés sont donc la pression normale de contact et l’expansion de surface. Le protocole de caractérisation du co-forgeage mis en place comporte trois essais « simples » permettant de solliciter les interfaces avec des pressions et des expansions différentes. Ces dernières, estimées par simulation numérique de l’essai, sont mises en relation avec la qualité des liaisons obtenues évaluée, quant à elle, au travers d’observations métallographiques. Les premières simulations permettent de dimensionner les campagnes expérimentales. Celles-ci sont ensuite conduites sur les moyens de mise en forme de la plateforme VULCAIN. Les efforts de mise en forme et la géométrie globale des pièces et la répartition de matière servent de base à l’identification des paramètres de la simulation. La simulation ainsi obtenue et les observations métallographiques aux interfaces sont ensuite mises en lien. Cette démarche a permis de confirmer l’importance du rôle joué par la pression de contact et l’expansion de surface sur l’établissement d’une liaison au cours de la mise en forme du multi-matériaux. La répartition et la forme des particules d’oxydes semblent liées au chemin thermomécanique subi par l’interface
The multi-material forging is a forming process allowing, simultaneously, the welding and shaping of multi-material parts with the right material at the right place. The purpose of the presented work is to identify the necessary conditions to obtain a metallurgical bond during forming between two different grades of steel. First, the state of the art allowed the identification of the physical phenomena occurring during multi-material forging and the determination of the key parameters of the bonding which are the contact pressure and the surface expansion at the both sides of the interface. The mechanisms to establish metallurgical bond by forging are based on the breaking and the dispersion of the oxide layer at the interface then the extrusion of the soft material through the voids generated between the oxide fragments. Second, the characterization methodology of this work is presented. It consists of three “simple” forming tests leading to different interface conditions (contact pressure and surface expansion). The first simulations allow the design of the experimental plan for each test. The comparison between simulations and experiments allows the identification of physical parameters of the simulation. Then, the contact pressure and the surface expansion of the identified simulations are used to analyze the metallographic structure and the bonding at the interface.The developed work confirms the major effect of the contact pressure and the surface expansion on the establishment of a metallurgical bond during multi-material forming. The size and the shape of the oxide particles seem to depend on the thermomechanical path at the interface
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Li, Huibin. "Towards three-dimensional face recognition in the real." Phd thesis, Ecole Centrale de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00998798.

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Due to the natural, non-intrusive, easily collectible, widespread applicability, machine-based face recognition has received significant attention from the biometrics community over the past three decades. Compared with traditional appearance-based (2D) face recognition, shape-based (3D) face recognition is more stable to illumination variations, small head pose changes, and varying facial cosmetics. However, 3D face scans captured in unconstrained conditions may lead to various difficulties, such as non-rigid deformations caused by varying expressions, data missing due to self occlusions and external occlusions, as well as low-quality data as a result of some imperfections in the scanning technology. In order to deal with those difficulties and to be useful in real-world applications, in this thesis, we propose two 3D face recognition approaches: one is focusing on handling various expression changes, while the other one can recognize people in the presence of large facial expressions, occlusions and large pose various. In addition, we provide a provable and practical surface meshing algorithm for data-quality improvement. To deal with expression issue, we assume that different local facial region (e.g. nose, eyes) has different intra-expression/inter-expression shape variability, and thus has different importance. Based on this assumption, we design a learning strategy to find out the quantification importance of local facial regions in terms of their discriminating power. For facial description, we propose a novel shape descriptor by encoding the micro-structure of multi-channel facial normal information in multiple scales, namely, Multi-Scale and Multi-Component Local Normal Patterns (MSMC-LNP). It can comprehensively describe the local shape changes of 3D facial surfaces by a set of LNP histograms including both global and local cues. For face matching, Weighted Sparse Representation-based Classifier (W-SRC) is formulated based on the learned quantification importance and the LNP histograms. The proposed approach is evaluated on four databases: the FRGC v2.0, Bosphorus, BU-3DFE and 3D-TEC, including face scans in the presence of diverse expressions and action units, or several prototypical expressions with different intensities, or facial expression variations combine with strong facial similarities (i.e. identical twins). Extensive experimental results show that the proposed 3D face recognition approach with the use of discriminative facial descriptors can be able to deal with expression variations and perform quite accurately over all databases, and thereby has a good generalization ability. To deal with expression and data missing issues in an uniform framework, we propose a mesh-based registration free 3D face recognition approach based on a novel local facial shape descriptor and a multi-task sparse representation-based face matching process. [...]
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Mesmay, Arnaud de. "Topics in low-dimensional computational topology." Paris, École normale supérieure, 2014. https://theses.hal.science/tel-04462650v1.

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La topologie, c’est-à-dire l’étude qualitative des formes et des espaces, constitue un domaine classique des mathématiques depuis plus d’un siècle, mais il n’est apparu que récemment que pour de nombreuses applications, il est important de pouvoir calculer informatiquement les propriétés topologiques d’un objet. Ce point de vue est la base de la topologie algorithmique, un domaine très actif à l’interface des mathématiques et de l’informatique auquel ce travail se rattache. Les trois contributions de cette thèse concernent le développement et l’étude d’algorithmes topologiques pour calculer des décompositions et des déformations d’objets de basse dimension, comme des graphes, des surfaces ou des 3-variétés. Le premier problème auquel nous nous attaquons traite de déformations : comment peut-on tester si deux graphes dessinés sur une même surface sont isotopes, c’est-à-dire si l’on peut déformer continûment l’un en l’autre ? Ce type de question est relié à des problèmes pratiques que l’on rencontre par exemple dans les systèmes d’information géographique ou les métamorphoses (morphings). En nous appuyant sur des concepts de géométrie hyperbolique et de la théorie des mapping class groups, nous établissons d’abord un critère combinatoire pour caractériser l’isotopie, ce qui reprouve et améliore un résultat de Ladegaillerie de 1984. Ensuite, en combinant ceci avec des algorithmes antérieurs pour tester l’homotopie de courbes, nous fournissons des algorithmes efficaces pour résoudre ce problème d’isotopie de graphes. Nous déplaçons ensuite notre étude vers des problèmes de décompositions, en nous intéressant à la découpe de surfaces le long de courbes ou de graphes respectant certaines propriétés topologiques, ce qui est une routine importante en algorithmique des graphes ou en infographie, parmi d’autres domaines. En établissant une forte connexion avec le cas continu, ainsi qu’en étudiant un modèle discret de surfaces aléatoires, nous améliorons les meilleures bornes connues pour plusieurs schémas de découpe. Cela prouve en particulier une conjecture de Przytycka et Przytycki datant de 1993, et fournit également un nouvel algorithme pour calculer des décompositions en pantalons courtes. Enfin, nous montons d’une dimension, où les meilleurs algorithmes connus pour de nombreux problèmes topologiques (comme le célèbre problème du noeud) sont exponentiels. La plupart de ces algorithmes reposent sur les surfaces normales, un objet omniprésent pour étudier les surfaces plongées dans une 3-variété. Nous étudions une relaxation naturelle de cette notion, les surfaces normales immergées, dont la meilleure structure algébrique en fait de bons candidats pour obtenir des algorithmes polynomiaux pour des problèmes topologiques. Dans ce travail, nous montrons qu’utiliser des surfaces normales immergées mène naturellement à un problème de détection de singularités, et nous prouvons que celui-ci est NP-dur ; c’est un résultat notable car l’on dispose de très peu de preuves de difficulté en topologie en 3 dimensions. Notre réduction s’appuie sur une connexion avec une classe restreinte de problèmes de satisfaction de contraintes qui a été partiellement classifiée par Feder
Topology is the area of mathematics investigating the qualitative properties of shapes and spaces. Although it has been a classical field of study for more than a century, it only appeared recently that being able to compute the topological features of various spaces might be of great value for many applications. This idea forms the core of the blossoming field of computational topology, to which this work belongs. The three contributions of this thesis deal with the development and the study of topological algorithms to compute deformations and decompositions of low-dimensional objects, such as graphs, surfaces or 3-manifolds. The first question we tackle concerns deformations: how can one test whether two graphs embedded on the same surface are isotopic, i. E. , whether one can be deformed continuously into the other? This kind of problems is relevant to practical problems arising with morphings or geographic information systems, for example. Relying on hyperbolic geometry and ideas from the theory of mapping class groups, we first establish a combinatorial criterion to characterize isotopy, reproving and strengthening a result of Ladegaillerie (1984). Combined with earlier algorithms on the homotopy of curves, this allows us in turn to provide efficient algorithms to solve this graph isotopy problem. We then shift our focus to decompositions, by investigating how to cut surfaces along curves or graphs with prescribed topological properties, which is an important routine in graph algorithms or computer graphics, amongst others domains. By establishing a strong connection with the continuous setting, as well as studying a discrete model for random surfaces, we improve the best known bounds for several instances of this problem. In particular, this proves a conjecture of Przytycka and Przytycki from 1993, and one of our new bounds readily translates into an algorithm to compute short pants decompositions. Finally, we move up one dimension, where the best known algorithms for many topological problems, like for example unknot recognition, are exponential. Most of these algorithms rely on normal surfaces, a ubiquitous tool to study the surfaces embedded in a 3-manifold. We investigate a relaxation of this notion called immersed normal surfaces, whose more convenient algebraic structure makes them good candidates to solve topological problems in polynomial time. We show that when working with immersed normal surfaces, a natural problem on the detection of singularities arises, and we prove it to be NP-hard – this is noteworthy as hardness results are very scarce in 3-dimensional topology. Our reduction works by establishing a connection with a restricted class of constraint satisfaction problems which has been partially classified by Feder
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Valdivia, Paola Tatiana Llerena. "Correção de normais para suavização de nuvens de pontos." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-19032014-145046/.

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Nos anos recentes, suavização de superfícies é um assunto de intensa pesquisa em processamento geométrico. Muitas das abordagens para suavização de malhas usam um esquema de duas etapas: filtragem de normais seguido de um passo de atualização de vértices para corresponder com as normais filtradas. Neste trabalho, propomos uma adaptação de tais esquemas de duas etapas para superfícies representadas por nuvens de pontos. Para isso, exploramos esquemas de pesos para filtrar as normais. Além disso, investigamos três métodos para estimar normais, analisando o impacto de cada método para estimar normais em todo o processo de suavização da superfície. Para uma análise quantitativa, além da comparação visual convencional, avaliamos a eficácia de diferentes opções de implementação usando duas medidas, comparando nossos resultados com métodos de suavização de nuvens de pontos encontrados a literatura
In the last years, surface denoising is a subject of intensive research in geometry processing. Most of the recent approaches for mesh denoising use a twostep scheme: normal filtering followed by a point updating step to match the corrected normals. In this work, we propose an adaptation of such two-step approaches for point-based surfaces, exploring three different weight schemes for filtering normals. Moreover, we also investigate three techniques for normal estimation, analyzing the impact of each normal estimation method in the whole point-set smoothing process. Towards a quantitative analysis, in addition to conventional visual comparison, we evaluate the effectiveness of different choices of implementation using two measures, comparing our results against state-of-art point-based denoising techniques. Keywords: surface smoothing; point-based surface; normal estimation; normal filtering.
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Lootens, Didier. "Ciments et suspensions concentrées modèles : écoulement, encombrement et floculation." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2004. http://tel.archives-ouvertes.fr/tel-00007217.

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Nous reportons ici le comportement rhéologique de suspensions concentrées - ou pâte - de particules granulaires ou colloïdales de ciment ou de silice sphérique et monodisperse. Le système modèle de particules de silice est utilisé pour pouvoir contrôler les propriétés physicochimiques de la suspension. Notre projet de recherche se centre sur deux points qui s'intéressent aux propriétés du coulis frais : (i) le premier est l'étude du processus de structuration par coagulation au repos et sa relation avec la prise. Nous avons utilisé des outils (ultrason, confocal) adaptés pour suivre et interpréter la coagulation et la prise du ciment.(ii). Le second est l'étude d'un phénomène de structuration dynamique, sous écoulement, typique des suspensions très concentrées et appelé " jamming ". Nous montrons que l'apparition de ce régime d'encombrement va de pair avec des fluctuations géantes de contraintes, avec une statistique caractéristique des événements critiques auto-organisés. L'état de surface des grains et du frottement intergranulaire est un paramètre important dans le blocage sous cisaillement. La simultanéité des fluctuations des efforts normaux et des efforts tangentiels aussi que des visualisations microscopiques suggère fortement que la formation de chaînes de contacts frottants est à l'origine du phénomène.
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Books on the topic "Surface normale"

1

Némethi, András. Normal Surface Singularities. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-06753-2.

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Angel, Abbud-Madrid, and United States. National Aeronautics and Space Administration., eds. Ignition and combustion characteristics of pure bulk metals: Normal-gravity test results : 32nd Aerospace Sciences Meeting & Exhibit, January 10-13, 1994/Reno, NV. Washington, D.C: American Institute of Aeronautics and Astronautics, 1994.

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Pahlawan, Rafid. Surface following and detection of the normal to a surface-application to ultrasonic-based pork carcass grading. Ottawa: National Library of Canada, 1996.

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Fröhlich, Steffen. Coulomb Frames in the Normal Bundle of Surfaces in Euclidean Spaces. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-29846-2.

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Fröhlich, Steffen. Coulomb Frames in the Normal Bundle of Surfaces in Euclidean Spaces: Topics from Differential Geometry and Geometric Analysis of Surfaces. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012.

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Branch, M. C. Ignition and combustion of bulk metals at normal, elevated, and reduced gravity: Annual technical report, NASA grant no. NAG-3-1685. Boulder, CO: Center for Combustion Research, University of Colorado at Boulder, 1995.

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E.N.S. Seminar (1983 Paris, France). Module des fibrés stables sur les courbes algébriques: Notes de l'Ecole normale supérieure, printemps, 1983. Edited by Le Potier Joseph 1944-, Verdier Jean Louis, and Ecole normale supérieure (France). Boston: Birkhäuser, 1985.

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Volovik, Mihail, I. Dolgov, and Natal'ya Muravina. THERMOGRAPHY SCREENING DISORDERS AND INJURIES OF PERIPHERAL NERVES Thermography Atlas. ru: INFRA-M Academic Publishing LLC., 2021. http://dx.doi.org/10.12737/textbook_61b1a3def1e114.93523951.

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Medical thermography is a non-invasive non-contact diagnostic method that allows to measure thermal radiation and visualize its distribution on the human body surface. The proposed atlas of thermograms is dedicated to the thermography diagnostic of disorders and injuries of peripheral nerves. Diagnostic criteria itself are based on the changes of normal temperature distribution in the area which is innervated by the disfunction nerve. All cases of pathology confirmed by reference methods and clinical data. The edition can be useful for neurologists, neurosurgeons, rehabilitation specialists, physiotherapists who treat the patients with the peripheral nerve pathology
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Tooze, Jennifer Anne. Cell surface and molecular expression of immunoregulatory determinants on B-Cell chronic lymphocytic leukaemia cells and their putative normal lineage counterparts. Uxbridge: Brunel University, 1993.

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United States. National Aeronautics and Space Administration., ed. Interim report entitled Computational and theoretical analysis of free surface flow in a thin liquid film under zero and normal gravity. [Washington, DC: National Aeronautics and Space Administration, 1989.

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Book chapters on the topic "Surface normale"

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Némethi, András. "Examples." In Normal Surface Singularities, 111–70. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-06753-2_5.

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Némethi, András. "Ehrhart Theory and the Seiberg–Witten Invariant." In Normal Surface Singularities, 501–60. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-06753-2_10.

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Némethi, András. "Resolution of Surface Singularities." In Normal Surface Singularities, 27–52. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-06753-2_2.

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Némethi, András. "The Link." In Normal Surface Singularities, 53–90. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-06753-2_3.

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Némethi, András. "Invariants Associated with a Resolution." In Normal Surface Singularities, 171–280. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-06753-2_6.

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Némethi, András. "Appendix. Complex Analytic Spaces." In Normal Surface Singularities, 665–78. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-06753-2_12.

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Némethi, András. "The Artin–Laufer Program." In Normal Surface Singularities, 281–344. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-06753-2_7.

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Némethi, András. "Introduction." In Normal Surface Singularities, 1–25. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-06753-2_1.

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Némethi, András. "Multivariable Divisorial Filtration." In Normal Surface Singularities, 345–431. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-06753-2_8.

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Némethi, András. "Lattice Cohomology." In Normal Surface Singularities, 561–664. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-06753-2_11.

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Conference papers on the topic "Surface normale"

1

Kovesi, P. "Shapelets correlated with surface normals produce surfaces." In Tenth IEEE International Conference on Computer Vision (ICCV'05) Volume 1. IEEE, 2005. http://dx.doi.org/10.1109/iccv.2005.224.

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Takacs, Peter Z., and Eugene L. Church. "Integrating Figure and Finish Measurements with Surface Profiling Instruments." In Surface Roughness and Scattering. Washington, D.C.: Optica Publishing Group, 1992. http://dx.doi.org/10.1364/surs.1992.stub3.

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Conventional figure measurement techniques are inadequate for testing aspheres for grazing incidence applications. Conventional techniques are best suited for optical components in the shape of flats, spheres, or conical surfaces of revolution, used mainly in normal incidence applications . These optics usually have their symmetry axis coincident with the local surface normal direction. Grazing incidence optics, on the other hand, are usually cylindrical, toroidal, or ellipsoidal in shape, with the symmetry axis intersection far outside the clear aperture. Such surfaces are not axisymmetric when viewed along their surface normals. They are highly anamorphic, having vastly different curvatures in the two directions parallel and perpendicular to the symmetry axis. It is extremely challenging to test these optical components during fabrication to insure that they indeed meet the specifications for figure and finish quality. It is because of the extreme difficulties involved in developing reliable tests with conventional interferometric techniques that we decided to use profiling techniques to characterize the figure and finish of synchrotron radiation (SR) optics.
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McLaren, Samuel, Isak Kilen, and Jerome V. Moloney. "Microscopic charge carrier dynamics within non-normal incidence VECSEL cavities." In Vertical-Cavity Surface-Emitting Lasers XXV, edited by Kent D. Choquette and Chun Lei. SPIE, 2021. http://dx.doi.org/10.1117/12.2583234.

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Gungor, Kivanc, Emre Unal, and Hilmi Volkan Demir. "Nanoplasmonic three-dimensional surfaces with strong surface-normal electric field enhancement." In 2013 IEEE Photonics Conference (IPC). IEEE, 2013. http://dx.doi.org/10.1109/ipcon.2013.6656563.

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Reid, Robert B., Mark E. Oxley, Michael T. Eismann, and Matthew E. Goda. "Quantifying surface normal estimation." In Defense and Security Symposium, edited by Dennis H. Goldstein and David B. Chenault. SPIE, 2006. http://dx.doi.org/10.1117/12.664161.

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Chen, Weifeng, Donglai Xiang, and Jia Deng. "Surface Normals in the Wild." In 2017 IEEE International Conference on Computer Vision (ICCV). IEEE, 2017. http://dx.doi.org/10.1109/iccv.2017.173.

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Halstead, Mark A., Brain A. Barsky, Stanley A. Klein, and Robert B. Mandell. "Reconstructing curved surfaces from specular reflection patterns using spline surface fitting of normals." In the 23rd annual conference. New York, New York, USA: ACM Press, 1996. http://dx.doi.org/10.1145/237170.237272.

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Bugaev, E. A., Anatoli I. Fedorenko, V. V. Kondratenko, and E. N. Zubarev. "Thermal stability of normal incidence multilayer mirrors for x-ray wavelength near carbon K-edge." In X-ray Optics and Surface Science, edited by Alexander V. Vinogradov. SPIE, 1995. http://dx.doi.org/10.1117/12.200278.

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Hou, Ming. "Perceptual localization of surface normal." In CHI '99 extended abstracts. New York, New York, USA: ACM Press, 1999. http://dx.doi.org/10.1145/632716.632754.

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Lenssen, Jan Eric, Christian Osendorfer, and Jonathan Masci. "Deep Iterative Surface Normal Estimation." In 2020 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR). IEEE, 2020. http://dx.doi.org/10.1109/cvpr42600.2020.01126.

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Reports on the topic "Surface normale"

1

Tasdizen, Tolga, and Ross Whitaker. Anisotropic Diffusion of Surface Normals for Feature Preserving Surface Reconstruction. Fort Belvoir, VA: Defense Technical Information Center, April 2003. http://dx.doi.org/10.21236/ada496496.

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Deutsch, M., B. M. Ocko, X. Z. Wu, E. B. Sirota, and S. K. Sinha. Surface crystallization in normal-alkanes and alcohols. Office of Scientific and Technical Information (OSTI), June 1995. http://dx.doi.org/10.2172/80963.

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Wu, X. Z., H. H. Shao, B. M. Ocko, M. Deutsch, S. K. Sinha, M. W. Kim, H. E. Jr King, and E. B. Sirota. Surface crystallization and thin film melting in normal alkanes. Office of Scientific and Technical Information (OSTI), December 1994. http://dx.doi.org/10.2172/10117552.

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Kiv, A. E., T. I. Maximova, and V. N. Soloviev. Microstructure of the relaxed (001) Si surface. [б. в.], December 1999. http://dx.doi.org/10.31812/0564/1245.

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We have applied molecular dynamics method and semi-empirical potential [1] to obtain the realistic picture of Si surface layers relaxation.The starting configuration was taken as a parallelepiped containing 864 atoms. There were 12 layers with 72 atoms in each one. Periodic boundary conditions were used in two dimensions. At first all atoms were in normal lattice positions. The relaxation of Si surface, which corresponds to (001) plane was investigated. MD method was applied in its standard form i.e. the equations of motion were solved by using of the central difference scheme. The time-step was 10-14s.
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Raymond, Kara, Laura Palacios, Cheryl McIntyre, and Evan Gwilliam. Status of climate and water resources at Chiricahua National Monument, Coronado National Memorial, and Fort Bowie National Historic Site: Water year 2019. National Park Service, May 2022. http://dx.doi.org/10.36967/nrr-2293370.

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Climate and hydrology are major drivers of ecosystems. They dramatically shape ecosystem structure and function, particularly in arid and semi-arid ecosystems. Understanding changes in climate, groundwater, and water quality and quantity is central to assessing the condition of park biota and key cultural resources. The Sonoran Desert Network collects data on climate, groundwater, and surface water at 11 National Park Service units in southern Arizona and New Mexico. This report provides an integrated look at climate, groundwater, and springs conditions at Chiricahua National Monument (NM), Coronado National Memorial (NMem), and Fort Bowie National Historic Site (NHS) during water year (WY) 2019 (October 2018–September 2019). Overall annual precipitation at Chiricahua NM and Coronado NMem in WY2019 was approximately the same as the normals for 1981–2010. (The weather station at Fort Bowie NHS had missing values on 275 days, so data were not presented for that park.) Fall and winter rains were greater than normal. The monsoon season was generally weaker than normal, but storm events related to Hurricane Lorena led to increased late-season rain in September. Mean monthly maximum temperatures were generally cooler than normal at Chiricahua, whereas mean monthly minimum temperatures were warmer than normal. Temperatures at Coronado were more variable relative to normal. The reconnaissance drought index (RDI) indicated that Chiricahua NM was slightly wetter than normal. (The WY2019 RDI could not be calculated for Coronado NMem due to missing data.) The five-year moving mean of annual precipitation showed both park units were experiencing a minor multi-year precipitation deficit relative to the 39-year average. Mean groundwater levels in WY2019 increased at Fort Bowie NHS, and at two of three wells monitored at Chiricahua NM, compared to WY2018. Levels in the third well at Chiricahua slightly decreased. By contrast, water levels declined in five of six wells at Coronado NMem over the same period, with the sixth well showing a slight increase over WY2018. Over the monitoring record (2007–present), groundwater levels at Chiricahua have been fairly stable, with seasonal variability likely caused by transpiration losses and recharge from runoff events in Bonita Creek. At Fort Bowie’s WSW-2, mean groundwater level was also relatively stable from 2004 to 2019, excluding temporary drops due to routine pumping. At Coronado, four of the six wells demonstrated increases (+0.30 to 11.65 ft) in water level compared to the earliest available measurements. Only WSW-2 and Baumkirchner #3 have shown net declines (-17.31 and -3.80 feet, respectively) at that park. Springs were monitored at nine sites in WY2019 (four sites at Chiricahua NM; three at Coronado NMem, and two at Fort Bowie NHS). Most springs had relatively few indications of anthropogenic or natural disturbance. Anthropogenic disturbance included modifications to flow, such as dams, berms, or spring boxes. Examples of natural disturbance included game trails, scat, or evidence of flooding. Crews observed 0–6 facultative/obligate wetland plant taxa and 0–3 invasive non-native species at each spring. Across the springs, crews observed six non-native plant species: common mullein (Verbascum thapsus), spiny sowthistle (Sonchus asper), common sowthistle (Sonchus oleraceus), Lehmann lovegrass (Eragrostis lehmanniana), rabbitsfoot grass (Polypogon monspeliensis), and red brome (Bromus rubens). Baseline data on water quality and water chemistry were collected at all nine sites. It is likely that that all nine springs had surface water for at least some part of WY2019, though temperature sensors failed at two sites. The seven sites with continuous sensor data had water present for most of the year. Discharge was measured at eight sites and ranged from < 1 L/minute to 16.5 L/minute.
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Moreland, Kenneth D. Milestone Completion Report WBS 1.3.5.05 ECP/VTK-m FY17Q3 [MS-17/02] Faceted Surface Normals STDA05-3. Office of Scientific and Technical Information (OSTI), July 2017. http://dx.doi.org/10.2172/1372614.

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Xu, Zhong. The Xu-Tec process of introducing normally solid materials into substrate surfaces. Office of Scientific and Technical Information (OSTI), December 1992. http://dx.doi.org/10.2172/7166766.

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Wilkowski, G. M., D. Rudland, P. Mincer, B. Metrovich, and D. Rider. L52249 Failure Initation Modes of Pipe with High Charpy Transition Temperature. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), May 2007. http://dx.doi.org/10.55274/r0012041.

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This report presents a methodology that determines the lowest temperature where ductile fracture would occur for either sharp cracks or blunt corrosion flaws in older low-toughness line pipe base metals. It is applicable to either axial or circumferential flaws in pipes under quasi-static loading, i.e., normal operating conditions with no sudden transient loads. The results showed that ductile initiation of a surface crack can occur at a significantly lower temperature than the Charpy transition temperature. A master curve of transition temperatures for different pipe thickness and crack geometries was developed and validated on 1927 and 1948 vintage pipes. The master-curve of transition temperatures comes from accounting for thickness effects, loading-rate effects, and constraint effects (for a surface crack) on the transition temperatures of the flawed pipe relative to the Charpy transition temperature. These transition temperature shifts were empirically determined from hundreds of past full-scale tests and literally thousands of laboratory tests, and then checked against data developed on much older vintage line pipe steels, i.e., the 1927 and 1948 pipes in this project.
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Dahal, Sachindra, and Jeffery Roesler. Passive Sensing of Electromagnetic Signature of Roadway Material for Lateral Positioning of Vehicle. Illinois Center for Transportation, November 2021. http://dx.doi.org/10.36501/0197-9191/21-039.

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Autonomous vehicles (AV) and advanced driver-assistance systems (ADAS) offer multiple safety benefits for drivers and road agencies. However, maintaining the lateral position of an AV or a vehicle with ADAS within a lane is a challenge, especially in adverse weather conditions when lane markings are occluded. For significant penetration of AV without compromising safety, vehicle-to-infrastructure sensing capabilities are necessary, especially during severe weather conditions. This research proposes a method to create a continuous electromagnetic (EM) signature on the roadway, using materials compatible with existing paving materials and construction methods. Laboratory testing of the proposed concept was performed on notched concrete-slab specimens and concrete prisms containing EM materials. An induction-based eddy-current sensor and magnetometers were implemented to detect the EM signature. The detected signals were compared to evaluate the effects of sensor height above the concrete surface, type of EM materials, EM-material volume, material shape, and volume of EM concrete prisms. A layer of up to 2 in. (5.1 cm) of water, ice, snow, or sand was placed between the sensor and the concrete slab to represent adverse weather conditions. Results showed that factors such as sensor height, EM-material volume, EM dosage, types of the EM material, and shape of the EM material in the prism were significant attenuators of the EM signal and must be engineered properly. Presence of adverse surface conditions had a negligible effect, as compared to normal conditions, indicating robustness of the presented method. This study proposes a promising method to complement existing sensors’ limitations in AVs and ADAS for effective lane-keeping during normal and adverse weather conditions with the help of vehicle-to-pavement interaction.
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Ennasr, Osama, Charles Ellison, Anton Netchaev, Ahmet Soylemezoglu, and Garry Glaspell. Unmanned ground vehicle (UGV) path planning in 2.5D and 3D. Engineer Research and Development Center (U.S.), August 2023. http://dx.doi.org/10.21079/11681/47459.

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Herein, we explored path planning in 2.5D and 3D for unmanned ground vehicle (UGV) applications. For real-time 2.5D navigation, we investigated generating 2.5D occupancy grids using either elevation or traversability to determine path costs. Compared to elevation, traversability, which used a layered approach generated from surface normals, was more robust for the tested environments. A layered approached was also used for 3D path planning. While it was possible to use the 3D approach in real time, the time required to generate 3D meshes meant that the only way to effectively path plan was to use a preexisting point cloud environment. As a result, we explored generating 3D meshes from a variety of sources, including handheld sensors, UGVs, UAVs, and aerial lidar.
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