Bibliografias temáticas / Estimation du flux de passagers

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Literatura científica selecionada sobre o tema "Estimation du flux de passagers"

Autor: Grafiati

Publicado: 28 de setembro de 2024

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Artigos de revistas sobre o assunto "Estimation du flux de passagers"

Li, H. Y., e W. M. Yan. "Inverse Convection Problem for Determining Wall Heat Flux in Annular Duct Flow". Journal of Heat Transfer 122, n.º 3 (29 de fevereiro de 2000): 460–64. http://dx.doi.org/10.1115/1.1287169.

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An inverse problem for unsteady forced convection in an annular duct is presented. The simulated temperature data taken at the outer wall are used to estimate the time-dependent axially varying surface heat flux distribution at the inner wall of the annular passage. No prior information on the functional form of the unknown wall heat flux is needed in the inverse method. The effects of the functional form of the wall heat flux, the number of the measurement points, and the measurement errors on the accuracy of the estimation are investigated. It is shown that the reconstruction of the timewise and spatial variations of the wall heat flux is satisfactory even if the estimated function is not smooth. [S0022-1481(00)01003-3]

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Thapar, Vikram, e Fernando A. Escobedo. "Simultaneous estimation of free energies and rates using forward flux sampling and mean first passage times". Journal of Chemical Physics 143, n.º 24 (28 de dezembro de 2015): 244113. http://dx.doi.org/10.1063/1.4938248.

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Papadogianni, Vasiliki N., Alexandros Romeos, Athanasios Giannadakis, Konstantinos Perrakis e Thrassos Panidis. "Fire Ignition and Propagation in Hidden Zones of Aircrafts: A Novel Confined Fire Apparatus (CFA) for Flame Spreading Investigation". Fire 6, n.º 8 (31 de julho de 2023): 292. http://dx.doi.org/10.3390/fire6080292.

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This research investigated potential fire hazards originating in hidden areas of pressurized sections of aircrafts. The objective was to establish a laboratory-scale flammability test method to predict the behavior of fire propagation under real fire conditions. A confined fire apparatus (CFA) was designed and constructed, and several tests were conducted to better understand the involved mechanisms and their consequences and to estimate flame spreading in hidden-zone fires. The experimental facility and flame-spreading results obtained for a typical material involved in hidden fires, specifically a ceiling panel, were presented and discussed. The experimental facility consisted of a narrow passage where a fire was initiated using a burner on a specimen exposed to a controlled heat flux. Experiments were conducted in the absence of forced airflow. Flame spreading was estimated through visual monitoring of fire development or temperature measurements at specific locations in the specimen. Both methods yielded similar results. The flame spread velocity in relation to the imposed heat flux allowed for the estimation of the critical heat flux for spreading q˙sp,cr″ and for ignition q˙ig,cr″; the corresponding temperatures, Ts,min and Tig; and the flame spread parameter Φ.

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Trentini, Anna, e Nicolas Malhene. "Maîtriser la coexistence des flux de passagers et de marchandises en milieu urbain". Revue Française de Gestion Industrielle 29, n.º 2 (1 de junho de 2010): 105–23. http://dx.doi.org/10.53102/2010.29.02.628.

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La mobilité urbaine regroupe à la fois la mobilité des personnes mais aussi la mobilité des biens. Aujourd'hui, l'intégration de la vision "passagers" dans la planification des transports ne fait aucun doute. Les marchandises, quand elles sont considérées, sont alors exprimées en tant que contraintes des flux passagers. Cet article propose un argumentaire mettant en avant les synergies de ces deux types de flux à priori antagonistes. Puis, la structure d'une procédure de planification de la mobilité est établie, son intérêt principal réside en la maîtrise de la coexistence des passagers/marchandises en ville. Pour cela, il s'agit de formaliser le cadre méthodologique de planification, d'analyser les éléments fondamentaux des approches méthodologiques de planification du transport de passagers et de marchandises et enfin d'identifier les concepts novateurs pour la définition d'une approche méthodologique de planification de la mobilité urbaine intégrée.

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Lin, Jingrou, Qingyang Sun, Yupeng Liu, Haijun Ye, Danling Tang, Xiaohao Zhang e Yang Gao. "Sea Surface pCO2 Response to Typhoon “Wind Pump” and Kuroshio Intrusion in the Northeastern South China Sea". Remote Sensing 16, n.º 1 (27 de dezembro de 2023): 123. http://dx.doi.org/10.3390/rs16010123.

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The Luzon Strait (LS) is a key region for estimating carbon sources and sinks in the South China Sea (SCS) and is highly influenced by the Kuroshio Current (KC) and typhoons. Understanding the variations in the sea surface partial pressure of carbon dioxide (pCO2-sw) under the combined effects of typhoons and KC in this region is crucial for estimating local and regional changes in ocean carbon flux. Based on valuable in situ pCO2-sw and remote sensing data, this study aimed to reveal the temporal variations and the physical mechanisms of pCO2-sw variations under the comprehensive effects of both typhoons and Kuroshio Intrusion (KI) in the LS. One week after the passage of the tropical cyclone (TC) Nanmadol, the concentration in the pCO2-sw and the influencing mechanisms varied in three different regions (W1–W3) on Transect A (120°E). In the region dominated by SCS waters (W1), the average pCO2-sw increased by 5.1 μatm after TC, which was mainly due to the TC “Wind Pump” inducing strong vertical mixing, which brought dissolved inorganic carbon (DIC)-rich deeper water up to the surface. In the region affected by KC (W2 and W3), pCO2-sw decreased after the TC (−8.2 μatm and −1.8 μatm, respectively) with TC-enhanced KI because the invasion of lower pCO2-sw of Kuroshio waters inhibited the TC-induced upwelling. More significant TC-induced upwelling (W3) would alleviate the decrease in pCO2-sw caused by the TC-enhanced KI. This study is a rare case providing a better understanding of the variations in pCO2-sw under TC-enhanced KI, which provides support for regional climate change prediction and carbon flux estimation in the western boundary current regions.

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Bhatt, Apoorva, Paweł Malecki e Dariusz Góra. "Shore Shadow Effect in Baikal". Universe 8, n.º 7 (24 de junho de 2022): 347. http://dx.doi.org/10.3390/universe8070347.

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The measurement of the individual charged particles especially muons in an extended air shower (EAS) resulting from primary cosmic rays provides important distinguishing parameters to identify the chemical composition of the cosmic primary particles. For Neutrino Telescope experiments like Baikal-GVD, the estimation of underwater muon flux is of importance to study atmospheric muons. In this paper, a GEANT4-based simulation is presented to estimate the atmospheric muon flux underwater taking Baikal-GVD as an example. The location of the Baikal-GVD experiment at Lake Baikal provides a unique opportunity to study the passage of muons through its northern shore and the water. The muons arriving from the north direction will lose more energy as compared to those arriving from the south. An approximation for the northern shore is also simulated in the GEANT4 geometry and the results of the simulation are compared with the measurements from the NT-96 detector. The results of the simulations are consistent with the shore shadow observed in the measurements in the NT-96. This approach can also be used to propagate the muons from generators like CORSIKA through long distances in matter like water, ice, earth, etc. for simulations in such experiments.

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Chen, Changsheng, R. C. Beardsley, Song Hu, Qichun Xu e Huichan Lin. "Using MM5 to Hindcast the Ocean Surface Forcing Fields over the Gulf of Maine and Georges Bank Region*". Journal of Atmospheric and Oceanic Technology 22, n.º 2 (1 de fevereiro de 2005): 131–45. http://dx.doi.org/10.1175/jtech-1682.1.

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Abstract The fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) is applied to the Gulf of Maine/Georges Bank (GoM/GB) region. This model is configured with two numerical domains with horizontal resolutions of 30 and 10 km, respectively, and driven by the NCAR-Eta weather model through a nested grid approach. Comparison of model-computed winds, wind stress, and heat flux with in situ data collected on moored meteorological buoys in the western GoM and over GB in 1995 shows that during the passage of atmospheric fronts over this region, MM5 provides a reasonable prediction of wind speed but not wind direction, and provides a relatively accurate estimation of longwave radiation but overestimates sensible and latent fluxes. The nudging data assimilation approach with inclusion of in situ wind data significantly improves the accuracy of the predicted wind speed and direction. Incorporation of the Fairall et al. air–sea flux algorithms with inclusion of Advanced Very High Resolution Radiometer (AVHRR)-derived SST improves the accuracy of the predicted latent and sensible heat fluxes in the GoM/GB region for both stable and unstable weather conditions.

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Gutiérrez-Jiménez, Eugenio, Changsi Cai, Irene Klærke Mikkelsen, Peter Mondrup Rasmussen, Hugo Angleys, Mads Merrild, Kim Mouridsen et al. "Effect of electrical forepaw stimulation on capillary transit-time heterogeneity (CTH)". Journal of Cerebral Blood Flow & Metabolism 36, n.º 12 (21 de julho de 2016): 2072–86. http://dx.doi.org/10.1177/0271678x16631560.

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Functional hyperemia reduces oxygen extraction efficacy unless counteracted by a reduction of capillary transit-time heterogeneity of blood. We adapted a bolus tracking approach to capillary transit-time heterogeneity estimation for two-photon microscopy and then quantified changes in plasma mean transit time and capillary transit-time heterogeneity during forepaw stimulation in anesthetized mice (C57BL/6NTac). In addition, we analyzed transit time coefficient of variance = capillary transit-time heterogeneity/mean transit time, which we expect to remain constant in passive, compliant microvascular networks. Electrical forepaw stimulation reduced, both mean transit time (11.3% ± 1.3%) and capillary transit-time heterogeneity (24.1% ± 3.3%), consistent with earlier literature and model predictions. We observed a coefficient of variance reduction (14.3% ± 3.5%) during functional activation, especially for the arteriolar-to-venular passage. Such coefficient of variance reduction during functional activation suggests homogenization of capillary flows beyond that expected as a passive response to increased blood flow by other stimuli. This finding is consistent with an active neurocapillary coupling mechanism, for example via pericyte dilation. Mean transit time and capillary transit-time heterogeneity reductions were consistent with the relative change inferred from capillary hemodynamics (cell velocity and flux). Our findings support the important role of capillary transit-time heterogeneity in flow-metabolism coupling during functional activation.

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Stevenson, Ian H., Anil Cherian, Brian M. London, Nicholas A. Sachs, Eric Lindberg, Jacob Reimer, Marc W. Slutzky, Nicholas G. Hatsopoulos, Lee E. Miller e Konrad P. Kording. "Statistical assessment of the stability of neural movement representations". Journal of Neurophysiology 106, n.º 2 (agosto de 2011): 764–74. http://dx.doi.org/10.1152/jn.00626.2010.

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In systems neuroscience, neural activity that represents movements or sensory stimuli is often characterized by spatial tuning curves that may change in response to training, attention, altered mechanics, or the passage of time. A vital step in determining whether tuning curves change is accounting for estimation uncertainty due to measurement noise. In this study, we address the issue of tuning curve stability using methods that take uncertainty directly into account. We analyze data recorded from neurons in primary motor cortex using chronically implanted, multielectrode arrays in four monkeys performing center-out reaching. With the use of simulations, we demonstrate that under typical experimental conditions, the effect of neuronal noise on estimated preferred direction can be quite large and is affected by both the amount of data and the modulation depth of the neurons. In experimental data, we find that after taking uncertainty into account using bootstrapping techniques, the majority of neurons appears to be very stable on a timescale of minutes to hours. Lastly, we introduce adaptive filtering methods to explicitly model dynamic tuning curves. In contrast to several previous findings suggesting that tuning curves may be in constant flux, we conclude that the neural representation of limb movement is, on average, quite stable and that impressions to the contrary may be largely the result of measurement noise.

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Villeneuve, Paul. "Le Québec et l’intégration continentale : un processus à plusieurs vitesses et à directions multiples". Cahiers de géographie du Québec 41, n.º 114 (12 de abril de 2005): 337–47. http://dx.doi.org/10.7202/022672ar.

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Les processus actuels d'intégration continentale en Amérique du Nord posent aux Québécois la question de leur appartenance territoriale. Historiquement, les géographes ont interprété la territorialité canadienne comme résultant des tensions entre deux champs d'interaction, l'un est-ouest, l'autre sud-nord. Selon la conjoncture, un des deux champs dominerait l'autre. L'article examine d'abord cette interprétation en explicitant la notion d'interaction spatiale. Ceci débouche sur une hypothèse empirique testée à l'aide de données préliminaires sur trois types d'interaction spatiale: les échanges de biens, les flux de passagers aériens et les images télévisuelles. Il appert que la continentalisation des champs d'interaction prend des formes différentes pour chaque type d'interaction, ce qui peut avoir des conséquences pour la territorialité québécoise.

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Mais fontes

Teses / dissertações sobre o assunto "Estimation du flux de passagers"

Drosouli, Ifigeneia. "Multimodal machine learning methods for pattern analysis in smart cities and transportation". Electronic Thesis or Diss., Limoges, 2024. http://www.theses.fr/2024LIMO0028.

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Dans le contexte des environnements urbains modernes et densément peuplés, la gestion efficace des transports et la structure des Systèmes de Transport Intelligents (STI) sont primordiales. Le secteur des transports publics connaît actuellement une expansion et une transformation significatives dans le but d'améliorer l'accessibilité, d'accommoder des volumes de passagers plus importants sans compromettre la qualité des déplacements, et d'adopter des pratiques respectueuses de l'environnement et durables. Les avancées technologiques, notamment dans l'Intelligence Artificielle (IA), l'Analyse de Données Massives (BDA), et les Capteurs Avancés (CA), ont joué un rôle essentiel dans la réalisation de ces objectifs et ont contribué au développement, à l'amélioration et à l'expansion des Systèmes de Transport Intelligents. Cette thèse aborde deux défis critiques dans le domaine des villes intelligentes, se concentrant spécifiquement sur l'identification des modes de transport utilisés par les citoyens à un moment donné et sur l'estimation et la prédiction du flux de transport au sein de divers systèmes de transport. Dans le contexte du premier défi, deux approches distinctes ont été développées pour la Détection des Modes de Transport. Tout d'abord, une approche d'apprentissage approfondi pour l'identification de huit médias de transport est proposée, utilisant des données de capteurs multimodaux collectées à partir des smartphones des utilisateurs. Cette approche est basée sur un réseau Long Short-Term Memory (LSTM) et une optimisation bayésienne des paramètres du modèle. À travers une évaluation expérimentale approfondie, l'approche proposée démontre des taux de reconnaissance remarquablement élevés par rapport à diverses approches d'apprentissage automatique, y compris des méthodes de pointe. La thèse aborde également des problèmes liés à la corrélation des caractéristiques et à l'impact de la réduction de la dimensionnalité. La deuxième approche implique un modèle basé sur un transformateur pour la détection des modes de transport appelé TMD-BERT. Ce modèle traite l'ensemble de la séquence de données, comprend l'importance de chaque partie de la séquence d'entrée, et attribue des poids en conséquence en utilisant des mécanismes d'attention pour saisir les dépendances globales dans la séquence. Les évaluations expérimentales mettent en évidence les performances exceptionnelles du modèle par rapport aux méthodes de pointe, soulignant sa haute précision de prédiction. Pour relever le défi de l'estimation du flux de transport, un Réseau Convolutif Temporel et Spatial (ST-GCN) est proposé. Ce réseau apprend à la fois des données spatiales du réseau de stations et des séries temporelles des changements de mobilité historiques pour prédire le flux de métro urbain et le partage de vélos à un moment futur. Le modèle combine des Réseaux Convolutifs Graphiques (GCN) et des Réseaux Long Short-Term Memory (LSTM) pour améliorer la précision de l'estimation. Des expériences approfondies menées sur des ensembles de données du monde réel du système de métro de Hangzhou et du système de partage de vélos de la ville de New York valident l'efficacité du modèle proposé, démontrant sa capacité à identifier des corrélations spatiales dynamiques entre les stations et à faire des prévisions précises à long terme
In the context of modern, densely populated urban environments, the effective management of transportation and the structure of Intelligent Transportation Systems (ITSs) are paramount. The public transportation sector is currently undergoing a significant expansion and transformation with the objective of enhancing accessibility, accommodating larger passenger volumes without compromising travel quality, and embracing environmentally conscious and sustainable practices. Technological advancements, particularly in Artificial Intelligence (AI), Big Data Analytics (BDA), and Advanced Sensors (AS), have played a pivotal role in achieving these goals and contributing to the development, enhancement, and expansion of Intelligent Transportation Systems. This thesis addresses two critical challenges within the realm of smart cities, specifically focusing on the identification of transportation modes utilized by citizens at any given moment and the estimation and prediction of transportation flow within diverse transportation systems. In the context of the first challenge, two distinct approaches have been developed for Transportation Mode Detection. Firstly, a deep learning approach for the identification of eight transportation media is proposed, utilizing multimodal sensor data collected from user smartphones. This approach is based on a Long Short-Term Memory (LSTM) network and Bayesian optimization of model’s parameters. Through extensive experimental evaluation, the proposed approach demonstrates remarkably high recognition rates compared to a variety of machine learning approaches, including state-of-the-art methods. The thesis also delves into issues related to feature correlation and the impact of dimensionality reduction. The second approach involves a transformer-based model for transportation mode detection named TMD-BERT. This model processes the entire sequence of data, comprehends the importance of each part of the input sequence, and assigns weights accordingly using attention mechanisms to grasp global dependencies in the sequence. Experimental evaluations showcase the model's exceptional performance compared to state-of-the-art methods, highlighting its high prediction accuracy. In addressing the challenge of transportation flow estimation, a Spatial-Temporal Graph Convolutional Recurrent Network is proposed. This network learns from both the spatial stations network data and time-series of historical mobility changes to predict urban metro and bike sharing flow at a future time. The model combines Graph Convolutional Networks (GCN) and Long Short-Term Memory (LSTM) Networks to enhance estimation accuracy. Extensive experiments conducted on real-world datasets from the Hangzhou metro system and the NY City bike sharing system validate the effectiveness of the proposed model, showcasing its ability to identify dynamic spatial correlations between stations and make accurate long-term forecasts

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Guesdon, Romain. "Estimation de poses humaines par apprentissage profond : application aux passagers des véhicules autonomes". Electronic Thesis or Diss., Lyon 2, 2024. http://www.theses.fr/2024LYO20002.

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La recherche concernant les voitures autonomes a fortement progressé ces dernières décennies, en se concentrant particulièrement sur l'analyse de l'environnement extérieur et sur les tâches liées à la conduite. Cela a permis une importante croissance de l'autonomie des véhicules particuliers. Dans ce nouveau contexte, il peut être pertinent de s'intéresser aux passagers de ces véhicules autonomes afin d'étudier le comportement de ces derniers face à cette révolution du moyen de transport. C'est pour approfondir ces thématiques que le projet région AURA AutoBehave a été mis en place. Ce projet réunit plusieurs laboratoires menant des recherches dans différentes disciplines scientifiques liées à cette thématique telles que la vision par ordinateur, la biomécanique, les émotions ou encore l'économie des transports. Cette thèse menée au laboratoire LIRIS s'inscrit donc dans ce projet, dans laquelle nous nous intéressons aux méthodes d'estimation de poses humaines des passagers par apprentissage profond. Nous avons d'abord étudié les solutions de l'état de l'art, et avons développé un jeu de données ainsi qu'une métrique plus adaptée aux contraintes de notre contexte. Nous nous sommes également intéressés à la visibilité des points afin d'aider l'estimation de la pose. Par la suite, nous nous sommes attaqués à la problématique de généralisation de domaine pour l'estimation de poses dans le but de proposer une solution efficace dans des conditions inconnues. Ainsi, nous nous sommes intéressés à la génération de données synthétiques de passagers pour l'estimation de poses afin de combler le manque de jeux de données annotés disponibles dans notre contexte. Nous avons étudié l'application de réseaux génératifs ainsi que de méthodes modélisation 3D à notre problématique. Nous nous sommes appuyés sur ces données pour proposer différentes stratégies d'entraînement et deux nouvelles architectures. L'approche par fusion proposée associée aux stratégies d'entraînement permet de tirer profit de jeux de données génériques et de jeux de données spécifiques, afin d'améliorer les capacités de généralisation des méthodes d'estimation de poses à l'intérieur d'une voiture, en particulier sur le bas du corps
Research into autonomous cars has made great strides in recent decades, focusing particularly on analysis of the external environment and driving-related tasks. This has led to a significant increase in the autonomy of private vehicles. In this new context, it may be relevant to take an interest in the passengers of these autonomous vehicles, to study their behavior in the face of this revolution in the means of transport. The AURA AutoBehave project has been set up to explore these issues in greater depth. This project brings together several laboratories conducting research in different scientific disciplines linked to this theme, such as computer vision, biomechanics, emotions, and transport economics. This thesis carried out at the LIRIS laboratory is part of this project, in which we focus on methods for estimating the human poses of passengers using deep learning. We first looked at state-of-the-art solutions and developed both a dataset and a metric better suited to the constraints of our context. We also studied the visibility of the keypoints to help estimate the pose. We then tackled the problem of domain generalisation for pose estimation to propose an efficient solution under unknown conditions. Thus, we focused on the generation of synthetic passenger data for pose estimation. Among other things, we studied the application of generative networks and 3D modeling methods to our problem. We have used this data to propose different training strategies and two new network architectures. The proposed fusion approach associated with the training strategies makes it possible to take advantage of both generic and specific datasets, to improve the generalisation capabilities of pose estimation methods inside a car, particularly on the lower body

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Shahnaz, Sabina. "Gas flux estimation from surface gas concentrations". Thesis, Georgia Institute of Technology, 2016. http://hdl.handle.net/1853/55073.

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A gradient-independent model of gas fluxes was formulated and tested. The model is built on the relationship between gas flux and the time history of surface gas concentration, known as half-order derivative (HOD), when the transport of the gas in the boundary layer is described by a diffusion equation. The eddy-diffusivity of gas is parameterized based on the similarity theory of boundary layer turbulence combined with the MEP model of surface heat fluxes. Test of the new model using in-situ data of CO2 concentration and fluxes at several locations with diverse vegetation cover, geographic and climatic conditions confirms its usefulness and potential for monitoring and modeling greenhouse gases. The proposed model may also be used for estimating other GHGS fluxes such as methane (CH4) and Water vapor flux. This proof-of-concept study justifies the proposed model as a practical solution for monitoring and modeling global GHGS budget over remote areas and oceans where ground observations of GHGS fluxes are limited or non-existent. One focus of the on-going research is to investigate its application to producing regional and global distributions of carbon fluxes for identifying sinks and sources of carbon and re-evaluating the regional and global carbon budget at monthly and annual time scales.

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Cordova, Vicente D. "Regional-scale carbon flux estimation using MODIS imagery". Virtual Press, 2005. http://liblink.bsu.edu/uhtbin/catkey/1325989.

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The National Aeronautics and Space Agency NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) platform carried by Terra and Aqua satellites, is providing systematic measurements summarized in high quality, consistent and well-calibrated satellite images and datasets ranging from reflectance in the visible and near infrared bands to estimates of leaf area index, vegetation indices and biome productivity. The objective of this research was to relate the spectral responses and derived MODIS products of ecosystems, to biogeochemical processes and trends in their physiological variables. When different sources of data were compared, discrepancies between the MODIS variables and the corresponding ground measurements were evident. Uncertainties in the input variables of MODIS products algorithms, effects of cloud cover at the studied pixel, estimation algorithm, and local variation in land cover type are considered as the cause. A simple "continuous field" model based on a physiologically-driven spectral index using two ocean-color bands of MODIS satellite sensor showed great potential to track seasonally changing photosynthetic light use efficiency and stress-induced reduction in net primary productivity of terrestrial vegetation. The model explained 88% of the variability in Flux tower-based daily Net Primary Productivity. Also a high correlation between midday gross CO2 exchange with both daily and 8-day mean gross CO2 exchange, consistent across all the studied vegetation types, was found. Although it may not be possible to estimate 8-day mean Light Use Efficiency reliably from satellite data, Light Use Efficiency models may still be useful for estimation of midday values of gross CO2 exchange which could then be related to longer term means of CO2 exchange. In addition, the MODIS enhanced vegetation index shows a high potential for estimation of ecosystem gross primary production, using respiration values from MODIS surface temperature, providing truly per-pixel estimates.
Department of Natural Resources and Environmental Management

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Goel, Gautam. "Dynamic flux estimation a novel framework for metabolic pathway analysis /". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31769.

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Thesis (Ph.D)--Biomedical Engineering, Georgia Institute of Technology, 2010.
Committee Chair: Voit, Eberhard O.; Committee Member: Butera, Robert; Committee Member: Chen, Rachel; Committee Member: Kemp, Melissa; Committee Member: Neves, Ana Rute. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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Bonnefous, Odile. "Estimation des vitesses d'écoulement des flux sanguins par échographie ultrasonore". Paris 7, 1986. http://www.theses.fr/1986PA077224.

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Cooper, Daniel Ira. "Estimation of sensible heat flux from remotely sensed surface temperatures". Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185151.

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A series of energy-balance experiments were performed over a winter wheat field in Southern Arizona. A Bowen ratio energy-balance system (BREB), anemometer, and thermal infrared thermometer (IRT) were placed in the center of the field on day 15 of 1988 shortly after germination. The BREB system generated 12-minute averages of net radiation, soil heat flux, latent energy, and sensible heat flux (H) throughout the season, terminating on day 152, just before harvest. On day 134, an eddy-correlation system was placed adjacent to the BREB system, where it collected H-data concurrently for 17 successive days. The data from the BREB and eddy-correlation systems were regressed against each other to quantify their field performance. The regression standard error (SE) between the two systems was ±40 W/m². BREB H-data was used as a "standard" to evaluate three different sensible heat flux models that are suitable for remote sensing applications. The three models require thermal canopy temperature, air temperature, and wind speed as input. Two of the three models use aerodynamic resistance theory, one of which is stability corrected, and the third remote-sensing model employs Monin-Obukhov turbulent transfer theory. The regression analysis between the BREB H-values and the three remote-sensing models shows that the stability corrected aerodynamic resistance model and the Monin-Obukhov model are capable of estimating H-values over a wide range of surface and atmospheric conditions.

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Comanescu, Mihai. "Flux and speed estimation techniques for sensorless control of induction motors". Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1116338965.

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Thesis (Ph.D.)--Ohio State University, 2005.
Title from first page of PDF file. Document formatted into pages; contains xv, 109 p.; also includes graphics. Includes bibliographical references (p. 106-109). Available online via OhioLINK's ETD Center

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Abareshi, Behzad. "Sensible heat flux estimation over a prairie grassland by neural networks". Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23765.

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Sensible heat flux, a key component of the surface energy balance, is difficult to estimate in practice. This study was conducted to see if backpropagation neural networks could estimate sensible heat flux by using horizontal wind speed, air temperature, radiometric surface temperature, net radiation, and time as input. Ground measurements from the First ISLSCP (International Satellite Land Surface Climatology Project) Field Experiment (FIFE), collected in 1987 and 1989 over a prairie grassland in Kansas, were used for network training and validation. Networks trained on part of the data from a narrow range of space-time coordinates performed well over the other part, with error (root mean square error divided by mean of observations) values as low as 0.24. This indicates the potential in neural networks for linking sensible heat flux to routinely measured meteorological variables and variables amenable to remote sensing. When the networks were tested with data from other space-times, performance varied from good to poor, with average error values around 1.26. This was mainly due to lack of input variables parameterizing canopy morphology and soil moisture, indicating that such variables should be incorporated in the design of future networks intended for large scale applications.

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Toffa, Ohini Kafui. "Estimation du flux optique en présence d'occultations par une approche TAC". Mémoire, Université de Sherbrooke, 2009. http://savoirs.usherbrooke.ca/handle/11143/4807.

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Nous proposons une résolution du problème de flux optique en présence d'occultations par une approche multi-résolution basée sur la topologie algébrique calculatoire (TAC). Plusieurs méthodes d'estimation du flux optique sont basées sur les contraintes d'intensité et de continuité spatiale du champ de vitesse et conduisent à la résolution d'une équation aux dérivées partielles (EDP).Nous proposons de résoudre le problème de lissage indésirable des contours d'occultation, produit par la contrainte de continuité spatiale, en exploitant le principe de diffusion non-linéaire basé sur le gradient multispectral du flux optique. En effet, le calcul du flux optique peut être interprété par le phénomène de réaction- diffusion du flux optique et le lissage des contours d'occultation est la conséquence du fait que la diffusion se fait d'une manière linéaire dans toute l'image. Une manière d'éviter ce problème est la modification de la conductivité de la diffusion à chaque pixel selon son appartenance au voisinage d'un contour d'occultation. Cela requiert une mesure de détection précise des contours d'occultation afin de les préserver.Nous montrons que le gradient multispectral du flux optique est une mesure qui convient.Nous utilisons l'alternative aux EDPs que représente l'approche TAC qui exploite les lois globales de la diffusion et les principes d'algèbre topologique afin d'offrir plus de robustesse et de précision dans les calculs.Nous utilisons également le modèle TAC multi-résolution pour résoudre le problème de validité de la contrainte d'intensité limitée à de petits décalages.Nous appliquons ensuite notre algorithme au recalage d'images par le flux optique.

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Livros sobre o assunto "Estimation du flux de passagers"

Fried, Jeremy Steven. Forest inventory-based estimation of carbon stocks and flux in California forests in 1990. Portland, OR: U.S. Dept. of Agriculture, Forest Service, Pacific Northwest Research Station, 2008.

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C, Euler H., Vaughan William W e United States. National Aeronautics and Space Administration., eds. Statistical technique for intermediate and long-range estimation of 13-month smoothed solar flux and geomagnetic index. [Marshall Space Flight Center], Ala: National Aeronautics and Space Administration, Marshall Space Flight Center, 1996.

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Snoussi, Mamma. Nature, estimation et comparaison des flux de matières issus des bassins versants de l'Adour (France), du Sebou, de l'Oum-er-Rbia et du Souss (Maroc): Impact du climat sur les apports fluviatiles à l'océan. Talence, France: Université de Bordeaux I, 1988.

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Muhamad, Nauman Malik. Inverse Estimation of Heat Flux and Temperature in 3D Finite Domain. Grin Verlag, 2016.

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Vaez-Zadeh, Sadegh. Parameter Estimation. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198742968.003.0007.

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In this chapter, the estimation of permanent magnetic synchronous (PMS) motor parameters, including stator winding resistance, motor inductances, and magnitude of permanent magnet flux linage, is presented in two main categories, i.e., offline and online. Several offline schemes, including DC and AC standstill tests, no-load test, load test, and vector control schemes, are presented for estimation of all the motor parameters. Major online schemes used in the estimation of PMS motor parameters are also presented in this chapter. They include closed-loop observer-based estimation, model reference adaptive system (MRAS)-based estimation, recursive least-squares (RLS) estimation, and extended Kalman filter scheme. The online schemes take into account the motor parameter variations during motor operation. The motor model, estimation procedure, and the connection of estimation systems to the motor control system are discussed for each parameter estimation scheme.

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Vaez-Zadeh, Sadegh. Rotor Position and Speed Estimation. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198742968.003.0006.

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The ultimate importance of rotor position and speed information in permanent magnet synchronous (PMS) machines control, and the industry interest to the rotor and speed sensorless systems as a cost-saving and practical alternative to the motor control with mechanical sensors are emphasized. Major position and speed estimation schemes are then presented in detail. These are the: back electromotive force (EMF)-based method; flux linkage method; hypothesis rotor position method; saliency-based method, including high frequency signal injection and inverter switching harmonics schemes; and finally, the observer-based method, including state observer and extended Kalman filter-based schemes. Each scheme was discussed by presenting the corresponding fundamental principles, followed by the appropriate motor model, estimation procedure, and the implementation. Demanding criteria such as accuracy, robustness, swiftness, and capability of working over the entire range of motor operation are discussed with each method.

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Statistical technique for intermediate and long-range estimation of 13-month smoothed solar flux and geomagnetic index. [Marshall Space Flight Center], Ala: National Aeronautics and Space Administration, Marshall Space Flight Center, 1996.

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Capítulos de livros sobre o assunto "Estimation du flux de passagers"

Karlaganis, G., e J. Dettwiler. "Areal Solute flux Estimation: Legal Aspects". In Field-Scale Water and Solute Flux in Soils, 289–94. Basel: Birkhäuser Basel, 1990. http://dx.doi.org/10.1007/978-3-0348-9264-3_27.

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Goudar, Chetan T., Richard Biener, James M. Piret e Konstantin B. Konstantinov. "Metabolic Flux Estimation in Mammalian Cell Cultures". In Animal Cell Biotechnology, 301–17. Totowa, NJ: Humana Press, 2007. http://dx.doi.org/10.1007/978-1-59745-399-8_14.

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Goudar, Chetan T., Richard K. Biener, James M. Piret e Konstantin B. Konstantinov. "Metabolic Flux Estimation in Mammalian Cell Cultures". In Animal Cell Biotechnology, 193–209. Totowa, NJ: Humana Press, 2013. http://dx.doi.org/10.1007/978-1-62703-733-4_13.

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Feng, Yong, Minghao Zhou e Xinghuo Yu. "Sliding-Mode Observer Based Flux Estimation of Induction Motors". In Intelligent Robotics and Applications, 530–39. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-33515-0_52.

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Holzhütter, Hermann-Georg, e Anke Schwendel. "Estimation of Enzymatic Flux Rates from Kinetic Isotope Experiments". In Modern Trends in Biothermokinetics, 103–7. Boston, MA: Springer US, 1993. http://dx.doi.org/10.1007/978-1-4615-2962-0_18.

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Zhang, Tong, Christiaan F. Labuschagne, Karen H. Vousden e Oliver D. K. Maddocks. "Direct Estimation of Metabolic Flux by Heavy Isotope Labeling Simultaneous with Pathway Inhibition: Metabolic Flux Inhibition Assay". In Metabolic Signaling, 109–19. New York, NY: Springer New York, 2018. http://dx.doi.org/10.1007/978-1-4939-8769-6_8.

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Abtew, Wossenu, e Assefa Melesse. "Crop Yield Estimation Using Remote Sensing and Surface Energy Flux Model". In Evaporation and Evapotranspiration, 161–75. Dordrecht: Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-94-007-4737-1_11.

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Sadiq, Muhammad Muneef, e Mohammad Asif. "Numerical Estimation of Interfacial Heat Flux Using Inverse Heat Conduction Method". In Proceedings of International Conference in Mechanical and Energy Technology, 577–88. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-2647-3_53.

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Karan, Vijay Kumar, P. R. Thakura e A. N. Thakur. "Adaptive Compensation Algorithm for Flux Estimation of PM BLDC Motor Drives". In Lecture Notes in Electrical Engineering, 795–801. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-8234-4_64.

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Susitra, D., B. Hema Malini e V. Meenakshi. "Estimation of Magnetic Flux Linkage in SRM Using Various Defuzzification Techniques". In Advances in Intelligent Systems and Computing, 11–20. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-2674-6_2.

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Trabalhos de conferências sobre o assunto "Estimation du flux de passagers"

Hong, Chungpyo, Yutaka Asako e Koichi Suzuki. "Performance of Parallel-Flow Gas-to-Gas Micro-Double-Tubes-Heat Exchangers". In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-12430.

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Heat transfer performance of two-stream parallel-flow gas-to-gas micro-double-tubes-heat exchangers was investigated numerically. The flow passages of the micro- double-tubes-heat exchanger are a circular tube for hot passage and a concentric annular tube for cold passage. A circular tube of r = 50 μm and a concentric annular tube of ri = 51 μm and ro = 71 μm with an identical cross-sectional area were chosen and the selected length was 20mm, respectively. Then, the partition wall is assumed to be a stainless steel tube with 1 μm in thickness. Numerical methodology is based on the arbitrary-Langrangian-Eulerian method. Computations were performed for wide flow range to find the effects of capacity ratio on the heat transfer characteristics of gas-to-gas micro-double-tubes-heat exchangers. The results are presented in form of temperature contours, bulk temperature, total temperatures and heat flux variation along the length. Also, the effectiveness and the number of transfer units approach and the estimation of the heat exchange rate were discussed.

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Chen, Jay Chung, e Lai Ah Wong. "Inverse Estimation of Estuary Flux". In Eighth International Conference on Estuarine and Coastal Modeling. Reston, VA: American Society of Civil Engineers, 2004. http://dx.doi.org/10.1061/40734(145)54.

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Ye, Shubo, Qingjun Zhao, Xiaorong Xiang, Guang Xi e Jianzhong Xu. "Modeling for Tip Clearance Effects on Stall-Onset Condition in Transonic Axial Compressors". In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-57081.

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Rotating stall is a primary limit to compressor performance, and the reasonable estimation of stall-onset point is very useful in compressor design. Extensive investigations have been conducted in the past few decades to develop analytical models and numerical methods for stall-onset prediction, and much progress has been made in the understanding of flow mechanism for rotating stall. In spite of the robust prediction ability of stall-onset condition, the unsteady 3-D computations are still time-consuming for industrial applications. Analytical models are able to provide a fast estimation of compressor stall onset. However, empirical correlations are usually needed in the analytical models, which leads to a decrement in the accuracy and application scope of the models. Especially for high speed compressors, tip clearance effects hasn’t been evaluated reasonably in the previous analytical models, which actually plays a very important role in determining the stall-onset point. Therefore, new analytical models accounting for tip clearance effects will be promising in estimating the stall-onset more precisely. It’s the requirement for a new analytical model that motivates the present work. In the present work, the unsteady flow simulation of a transonic compressor rotor at near stall condition was performed to clarify the relations between tip clearance flow oscillations and compressor stall-onset in transonic axial compressor rotors. The interaction between tip clearance and incoming flow is simplified to a 2-D analogy of free-stream and counter-flow wall jet interaction. Momentum balance analysis is applied to identify the position of tip clearance/incoming flow interface, together with a prediction method of tip leakage vortex core trajectory. The effects of the in-passage shock on tip clearance/incoming flow interaction is taken into account by applying an upstream deflection of the interface, and this deflection is also observed in the computational flow field at near stall conditions. As a combination of the above-mentioned aspects, a model is proposed to define the critical point for tip clearance flow spillage from blade leading edge, which corresponds to the stall-onset point on compressor performance curves. Validations against numerical results prove that the model is capable of including tip clearance effects on stall-onset point. Parametric study of the model shows that blade tip offloads with increasing tip clearance, reducing the inverse momentum flux of tip clearance flow. As a result, the stalling flow coefficient appears to be less sensitive to tip clearance variation, which accords with the published experimental results.

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Fadgyas, M. C., M. V. Pricop, M. L. Niculescu, M. G. Cojocaru e A. Dumitrache. "Fast computational hypersonic heat flux estimation". In INTERNATIONAL CONFERENCE OF NUMERICAL ANALYSIS AND APPLIED MATHEMATICS (ICNAAM 2017). Author(s), 2018. http://dx.doi.org/10.1063/1.5043974.

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Chrysoulakis, Nektarios, Mattia Marconcini, Jean-Philippe Gastellu-Etchegorry, C. S. B. Grimmong, Christian Feigenwinter, Fredrik Lindberg, Fabio Del Frate et al. "ANthropogenic heat FLUX estimation from Space". In 2017 Joint Urban Remote Sensing Event (JURSE). IEEE, 2017. http://dx.doi.org/10.1109/jurse.2017.7924591.

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Klammler, H., K. Hatfield, J. Luz, M. Annable, M. Newman, J. Cho, A. Peacock, V. Stucker, J. Ranville e C. Clark. "Water and contaminant flux estimation from multi-layer passive flux meter measurements". In AFM2012. Southampton, UK: WIT Press, 2012. http://dx.doi.org/10.2495/afm120271.

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Starcic, Antonio, Anita Martincevic e Mario Vasak. "Estimation of disturbance heat flux in buildings". In 2015 IEEE Sensors Applications Symposium (SAS). IEEE, 2015. http://dx.doi.org/10.1109/sas.2015.7133615.

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Athavale, Apoorva, Kensuke Sasaki, Takashi Kato e Robert D. Lorenz. "Magnetization state estimation in variable-flux PMSMs". In 2017 IEEE International Electric Machines and Drives Conference (IEMDC). IEEE, 2017. http://dx.doi.org/10.1109/iemdc.2017.8002081.

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Cheewoo Lee. "Estimation of flux linkage by analyzing flux paths in a switched reluctance motor". In 2012 IEEE Vehicle Power and Propulsion Conference (VPPC). IEEE, 2012. http://dx.doi.org/10.1109/vppc.2012.6422788.

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Yan, Zhengzhang, Junlei Zhu e Jiahao Chen. "PM Flux Linkage and Offset Voltage Adaptive Flux Estimation in AC Motor Drives". In 2024 IEEE 10th International Power Electronics and Motion Control Conference (IPEMC2024-ECCE Asia). IEEE, 2024. http://dx.doi.org/10.1109/ipemc-ecceasia60879.2024.10567649.

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Relatórios de organizações sobre o assunto "Estimation du flux de passagers"

Martz, R. L., R. C. Gast e L. J. Tyburski. Monte Carlo next-event point flux estimation for RCP01. Office of Scientific and Technical Information (OSTI), dezembro de 1991. http://dx.doi.org/10.2172/10193014.

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Michael P. Bacon e Roger Francois. Estimation of Particle Flux and Remineralization Rate from Radioactive Disequilibrium. Office of Scientific and Technical Information (OSTI), maio de 2004. http://dx.doi.org/10.2172/824247.

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McLaughlin, David J. UMass Participation in Air-Sea Flux Estimation in High Wind Boundary Layers. Fort Belvoir, VA: Defense Technical Information Center, agosto de 2001. http://dx.doi.org/10.21236/ada625696.

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McLaughlin, David J. UMass Participation in Air-Sea Flux Estimation in High Wind Boundary Layers. Fort Belvoir, VA: Defense Technical Information Center, setembro de 2002. http://dx.doi.org/10.21236/ada627311.

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Fried, Jeremy S., e Xiaoping Zhou. Forest inventory-based estimation of carbon stocks and flux in California forests in 1990. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, 2008. http://dx.doi.org/10.2737/pnw-gtr-750.

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KAPLAN, DANIEL. Estimation of Tritium Annual Flux From Concrete Rubble Buried in the E-Area Slit Trenches. Office of Scientific and Technical Information (OSTI), agosto de 2004. http://dx.doi.org/10.2172/835581.

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Fourrier, Marine. Integration of in situ and satellite multi-platform data (estimation of carbon flux for trop. Atlantic). EuroSea, 2023. http://dx.doi.org/10.3289/eurosea_d7.6.

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This report presents the results of task 7.3 on “Quantification of improvements in carbon flux data for the tropical Atlantic based on the multi-platform and neural network approach”. To better constrain changes in the ocean’s capture and sequestration of CO2 emitted by human activities, in situ measurements are needed. Tropical regions are considered to be mostly sources of CO2 to the atmosphere due to specific circulation features, with large interannual variability mainly controlled by physical drivers (Padin et al., 2010). The tropical Atlantic is the second largest source, after the tropical Pacific, of CO2 to the atmosphere (Landschützer et al., 2014). However, it is not a homogeneous zone, as it is affected by many physical and biogeochemical processes that vary on many time scales and affect surrounding areas (Foltz et al., 2019). The Tropical Atlantic Observing System (TAOS) has progressed substantially over the past two decades. Still, many challenges and uncertainties remain to require further studies into the area’s role in terms of carbon fluxes (Foltz et al., 2019). Monitoring and sustained observations of surface oceanic CO2 are critical for understanding the fate of CO2 as it penetrates the ocean and during its sequestration at depth. This deliverable relies on different observing platforms deployed specifically as part of the EuroSea project (a Saildrone, and 5 pH-equipped BGC-Argo floats) as well as on the platforms as part of the TAOS (CO2-equipped moorings, cruises, models, and data products). It also builds on the work done in D7.1 and D7.2 on the deployment and quality control of pH-equipped BGC-Argo floats and Saildrone data. Indeed, high-quality homogeneously calibrated carbonate variable measurements are mandatory to be able to compute air-sea CO2 fluxes at a basin scale from multiple observing platforms. (EuroSea Deliverable, D7.6)

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Hughes, J. C., A. F. Henry, D. D. Lanning e J. A. Bernard. An experimental evaluation of the instrumented flux synthesis method for the real-time estimation of reactivity. Final report. Office of Scientific and Technical Information (OSTI), janeiro de 1996. http://dx.doi.org/10.2172/167217.

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Liu, X., Z. Chen e S. E. Grasby. Using shallow temperature measurements to evaluate thermal flux anomalies in the southern Mount Meager volcanic area, British Columbia, Canada. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/330009.

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Geothermal is a clean and renewable energy resource. However, locating where elevated thermal gradient anomalies exist is a significant challenge when trying to assess potential resource volumes during early exploration of a prospective geothermal area. In this study, we deployed 22 temperature probes in the shallow subsurface along the south flank of the Mount Meager volcanic complex, to measure the transient temperature variation from September 2020 to August 2021. In our data analysis, a novel approach was developed to estimate the near-surface thermal distribution, and a workflow and code with python language have been completed for the thermal data pre-processing and analysis. The long-term temperature variation at different depths can be estimated by modelling, so that the relative difference of deducing deeper geothermal gradient anomalies can be assessed. Our proposed inversion and simulation methods were applied to calculating the temperature variation at 2.0 meters depth. The results identified a preferred high thermal flux anomalous zone in the south Mount Meager area. By combining with previous studies, the direct analysis and estimation of anomalous thermal fields based on the collected temperature data can provide a significant reference for interpretation of the regional thermal gradient variation.

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Kamai, Tamir, Gerard Kluitenberg e Alon Ben-Gal. Development of heat-pulse sensors for measuring fluxes of water and solutes under the root zone. United States Department of Agriculture, janeiro de 2016. http://dx.doi.org/10.32747/2016.7604288.bard.

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The objectives defined for this study were to: (1) develop a heat-pulse sensor and a heat-transfer model for leaching measurement, and (2) conduct laboratory study of the sensor and the methodology to estimate leaching flux. In this study we investigated the feasibility for estimating leachate fluxes with a newly designed heat-pulse (HP) sensor, combining water flux density (WFD) with electrical conductivity (EC) measurements in the same sensor. Whereas previous studies used the conventional heat pulse sensor for these measurements, the focus here was to estimate WFD with a robust sensor, appropriate for field settings, having thick-walled large-diameter probes that would minimize their flexing during and after installation and reduce associated errors. The HP method for measuring WFD in one dimension is based on a three-rod arrangement, aligned in the direction of the flow (vertical for leaching). A heat pulse is released from a center rod and the temperature response is monitored with upstream (US) and downstream (DS) rods. Water moving through the soil caries heat with it, causing differences in temperature response at the US and DS locations. Appropriate theory (e.g., Ren et al., 2000) is then used to determine WFD from the differences in temperature response. In this study, we have constructed sensors with large probes and developed numerical and analytical solutions for approximating the measurement. One-dimensional flow experiments were conducted with WFD ranging between 50 and 700 cm per day. A numerical model was developed to mimic the measurements, and also served for the evaluation of the analytical solution. For estimation WFD, and analytical model was developed to approximate heat transfer in this setting. The analytical solution was based on the work of Knight et al. (2012) and Knight et al. (2016), which suggests that the finite properties of the rods can be captured to a large extent by assuming them to be cylindrical perfect conductors. We found that: (1) the sensor is sensitive for measuring WFD in the investigated range, (2) the numerical model well-represents the sensor measurement, and (2) the analytical approximation could be improved by accounting for water and heat flow divergence by the large rods.

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