Spelling suggestions: "subject:"bayesian algorithm"" "subject:"eayesian algorithm""
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The Integrated Distributed Hydrological Model, ECOFLOW- a Tool for Catchment ManagementSokrut, Nikolay January 2005 (has links)
<p>In order to find effective measures that meet the requirements for proper groundwater quality and quantity management, there is a need to develop a Decision Support System (DSS) and a suitable modelling tool. Central components of a DSS for groundwater management are thought to be models for surface- and groundwater flow and solute transport. The most feasible approach seems to be integration of available mathematical models, and development of a strategy for evaluation of the uncertainty propagation through these models. The physically distributed hydrological model ECOMAG has been integrated with the groundwater model MODFLOW to form a new integrated watershed modelling system - ECOFLOW. The modelling system ECOFLOW has been developed and embedded in Arc View. The multiple-scale modelling principle, combines a more detailed representation of the groundwater flow conditions with lumped watershed modelling, characterised by simplicity in model use, and a minimised number of model parameters. A Bayesian statistical downscaling procedure has also been developed and implemented in the model. This algorithm implies downscaling of the parameters used in the model, and leads to decreasing of the uncertainty level in the modelling results. The integrated model ECOFLOW has been applied to the Vemmenhög catchment, in Southern Sweden, and the Örsundaån catchment, in central Sweden. The applications demonstrated that the model is capable of simulating, with reasonable accuracy, the hydrological processes within both the agriculturally dominated watershed (Vemmenhög) and the forest dominated catchment area (Örsundaån). The results show that the ECOFLOW model adequately predicts the stream and groundwater flow distribution in these watersheds, and that the model can be used as a possible tool for simulation of surface– and groundwater processes on both local and regional scales. A chemical module ECOMAG-N has been created and tested on the Vemmenhög watershed with a highly dense drainage system and intensive fertilisation practises. The chemical module appeared to provide reliable estimates of spatial nitrate loads in the watershed. The observed and simulated nitrogen concentration values were found to be in close agreement at most of the reference points. The proposed future research includes further development of this model for contaminant transport in the surface- and ground water for point and non-point source contamination modelling. Further development of the model will be oriented towards integration of the ECOFLOW model system into a planned Decision Support System.</p>
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The Integrated Distributed Hydrological Model, ECOFLOW- a Tool for Catchment ManagementSokrut, Nikolay January 2005 (has links)
In order to find effective measures that meet the requirements for proper groundwater quality and quantity management, there is a need to develop a Decision Support System (DSS) and a suitable modelling tool. Central components of a DSS for groundwater management are thought to be models for surface- and groundwater flow and solute transport. The most feasible approach seems to be integration of available mathematical models, and development of a strategy for evaluation of the uncertainty propagation through these models. The physically distributed hydrological model ECOMAG has been integrated with the groundwater model MODFLOW to form a new integrated watershed modelling system - ECOFLOW. The modelling system ECOFLOW has been developed and embedded in Arc View. The multiple-scale modelling principle, combines a more detailed representation of the groundwater flow conditions with lumped watershed modelling, characterised by simplicity in model use, and a minimised number of model parameters. A Bayesian statistical downscaling procedure has also been developed and implemented in the model. This algorithm implies downscaling of the parameters used in the model, and leads to decreasing of the uncertainty level in the modelling results. The integrated model ECOFLOW has been applied to the Vemmenhög catchment, in Southern Sweden, and the Örsundaån catchment, in central Sweden. The applications demonstrated that the model is capable of simulating, with reasonable accuracy, the hydrological processes within both the agriculturally dominated watershed (Vemmenhög) and the forest dominated catchment area (Örsundaån). The results show that the ECOFLOW model adequately predicts the stream and groundwater flow distribution in these watersheds, and that the model can be used as a possible tool for simulation of surface– and groundwater processes on both local and regional scales. A chemical module ECOMAG-N has been created and tested on the Vemmenhög watershed with a highly dense drainage system and intensive fertilisation practises. The chemical module appeared to provide reliable estimates of spatial nitrate loads in the watershed. The observed and simulated nitrogen concentration values were found to be in close agreement at most of the reference points. The proposed future research includes further development of this model for contaminant transport in the surface- and ground water for point and non-point source contamination modelling. Further development of the model will be oriented towards integration of the ECOFLOW model system into a planned Decision Support System. / QC 20101007
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Méthode et outils pour l'identification de défauts des bâtiments connectés performants / Method and tools for fault detection in smart high-performance buildingsJosse, Rozenn 13 November 2017 (has links)
Ces travaux de thèse portent sur le développement d’une nouvelle méthodologie pour l’identification de défauts de bâtiments performants et connectés afin d'aider à la garantie de performances. Nous avons dans un premier temps resitué nos travaux dans le contexte énergétique actuel en montrant le rôle majeur des bâtiments dans la réduction des consommations énergétiques. Nous avons ensuite présenté notre méthodologie en argumentant sur les techniques à utiliser avant d’effectuer un choix final. Cette méthodologie se compose de deux blocs principaux : le premier vise à réduire les incertitudes liées à l'occupant et à l'environnement et le second étudie l'écart entre la simulation et la mesure par une analyse de sensibilité couplée à un algorithme bayésien. Nous l'avons ensuite implémentée dans un outil que nous avons nommé REFATEC. Nous avons alors soumis notre méthodologie à différents tests dans des conditions idéales afin d’éprouver sa précision et son temps d’exécution. Cette étape a montré que la méthodologie est efficace mais montre quelques faiblesses dans le cas d’une saison estivale ou d’un défaut très localisé. Enfin, nous l’avons mise en situation face à un cas réel afin de traiter les nombreuses questions que soulèvent l’utilisation de mesures in-situ dans la perspective de la garantie de performances et de la détection de défauts, avec notamment la fiabilité des mesures et les incertitudes encore nombreuses qui doivent être traitées. / This thesis deals with the development of a new methodology for fault detection within smart high-performance buildings helping the performance guarantee. We first have placed our work in the current energy context by focusing on the major role of buildings in the decrease of energy consumption. Then we introduced our methodology and we argued about various techniques that could be used before making a choice. This methodology is made up of two main parts : the former reduces the uncertainties due to the occupant and the environment and the latter studies the gap between simulation and measurements thanks to a sensitivity analysis coupled with a bayesian algorithm. Then we implemented it within a tool that we named REFATEC. We carried out various tests in controlled conditions in order to evaluate its precision and its calculation time. This step showed that our methodology is effective but it has some difficulties when the studied period is during summer or when the faults are very located. is a very located fault. Eventually we confronted our methodology to a real case where we faced numerous questions that appear when dealing with measurements, especially their reliability and the uncertainties that still need to be taken care of, in the perspective of performance guarantee and fault detection.
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