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Chen, Liping Acevedo Miguel Felipe. "Soil characteristics estimation and its application in water balance dynamics." [Denton, Tex.] : University of North Texas, 2008. http://digital.library.unt.edu/permalink/meta-dc-9789.
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Chen, Liping. "Soil Characteristics Estimation and Its Application in Water Balance Dynamics." Thesis, University of North Texas, 2008. https://digital.library.unt.edu/ark:/67531/metadc9789/.
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This thesis is a contribution to the work of the Texas Environmental Observatory (TEO), which provides environmental information from the Greenbelt Corridor (GBC) of the Elm Fork of the Trinity River. The motivation of this research is to analyze the short-term water dynamic of soil in response to the substantial rainfall events that occurred in North Texas in 2007. Data collected during that year by a TEO soil and weather station located at the GBC includes precipitation, and soil moisture levels at various depths. In addition to these field measurements there is soil texture data obtained from lab experiments. By comparing existing water dynamic models, water balance equations were selected for the study as they reflect the water movement of the soil without complicated interrelation between parameters. Estimations of water flow between soil layers, infiltration rate, runoff, evapotranspiration, water potential, hydraulic conductivity, and field capacity are all obtained by direct and indirect methods. The response of the soil at field scale to rainfall event is interpreted in form of flow and change of soil moisture at each layer. Additionally, the analysis demonstrates that the accuracy of soil characteristic measurement is the main factor that effect physical description. Suggestions for model improvement are proposed. With the implementation of similar measurements over a watershed area, this study would help the understanding of basin-scale rainfall-runoff modeling.
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Rim, Chang-Soo. "Daily estimation of local evapotranspiration using energy and water balance approaches." Diss., The University of Arizona, 1995. http://hdl.handle.net/10150/191190.
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Meteorological and environmental (i.e. soil water content) data measured from semiarid watersheds (Lucky Hills and Kendall) during the summer rainy and winter periods were used to study the interrelationships between variables, and to evaluate the effects of variables on the daily estimation of actual evapotranspiration (AET). The relationship between AET and potential evapotranspiration (PET) as a function of an environmental factor was the major consideration of this research. The relationship between AET and PET as a function of soil water content as suggested by Thornthwaite-Mather, Morton and Priestley-Taylor was studied to determine its applicability to the study area. Furthermore, multiple linear regression (MLR) analysis was employed to evaluate the order of importance of the meteorological and soil water factors involved. Finally, the information gained was used for MLR model development. The results of MLR analysis showed that the combined effects of available energy, soil water content and wind speed were responsible for 77 % of the observed variations in AET at Lucky Hills watershed and 70 % at Kendall watershed during the summer rainy period. The analyses also indicated that the combined effects of available energy, vapor pressure deficit and wind speed were responsible for 70 % of the observed variations in AET at Lucky Hills watershed and 72 % at Kendall watershed during the winter period. However, the test results of three different approaches, using the relationships between AET and PET as a function of soil water content indicated some inadequacy. The low correlation between PET, AET, and soil moisture conditions raised some doubt concerning the validity of methods developed elsewhere, and indicated the effects of energy availability on the relationship between PET, AET, and soil water content regardless of the soil water condition. In contrast, agreement between observed AET and estimated AET from MLR models during the summer rainy and winter periods at both watersheds indicated that MLR models can give reasonable estimates of AET, at least under the climatic conditions in which the formulae were developed.
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Jaedicke, Christian. "Lake Evaporation Estimation by Isotope, Energy Balance and Bulk Aerodynamic Methods." Thesis, Uppsala universitet, Institutionen för geovetenskap, 1997. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-393212.
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Lake evaporation from a shallow lake in central Sweden has been estimated using three independent methods from measurements during summer 1995. The applied isotope method is a combination of the water and isotope mass balance. Its main feature is that inflows need not to be measured. Only knowledge of their isotopic content is sufficient. For calculations by the bulk aerodynamic method a computer program was applied, which takes into account the different conditions of stratification. The energy balance of the lake was determined by using the short and long wave radiation, heat storage and advective heat energy. Measurements were done on a small island and at a mast in the middle of the lake. Evaporation estimated by all the methods varied from -1.1 to 5.0 mm/d during the summer months 1995. Values estimated by the energy balance method agreed well with those from the bulk aerodynamic method. Evaporation estimates from the isotope method a showed fairly good agreement with the two other methods, excepting a few periods. It was found that both the isotope as well as the energy balance method are sensitive to errors in lake volume. Both methods carry some uncertainty due to their dependence on water balance components, some of which are difficult to determine. The bulk aerodynamic method is independent of the water balance of the lake. A good accuracy can be achieved using only four variables i.e. wind speed, relative humidity, skin and air temperature.<br>Avdunstningen från den grunda sjön Tämnaren i centrala Sverige bestämdes med tre oberoende metoder ur mätningar från sommaren 1995. Den använda isotopmetoden är en kombination av vatten- och isotopbalansen. Dess viktigaste fördel är att inflödet inte behöver mätas, utan att kännedom om isotophalten är tillräcklig. För beräkningarna med den bulk-aerodynamiska metoden användes ett datorprogram som tar hänsyn till atmosfärens stabilitet. Energibalansen beräknades ur kort- och långvågsstrålningen, värmelagringen och den tillförda energin. Mätningarna utfördes dels på en liten ö och dels vid en mast mitt i sjön. Avdunstningen varierade mellan -1.1 mmd-1 till 5.0 mmd-1. Resultaten från energibalansmetoden överenstämde bra med resultaten från den bulk-aerodynamiska metoden. Även resultaten från isotopmetoden överenstämde bra med resultaten från de två andra metoderna, med undantag av några få perioder. Både isotop- och energibalansmetoden var känsliga för feluppskattningar av sjövolymen. Båda metoderna innehåller osäkerheter som en följd av deras beroende på vissa av vattenbalansens komponenter, som är svåra att bestämma. Den bulk-aerodynamiska metoden är oberoende av sjöns vattenbalans och en bra noggranhet kan uppnås med mätningar av endast de fyra variablerna vindhastighet, relativ fuktighet, yt- och lufttemperatur.<br>Die Verdunstung von einem flachen See in Zentralschweden wurde mit Hilfe von drei unabhängigen Methoden bestimmt. Die Messungen wurden im Sommer 1995 durchgeführt. Die angewandte Isotopenmethode ist eine Kombination aus Wasserbilanz and lsotop-Massenbilanz. Das besondere Merkmal dieser Methode ist es, daß Zuflüsse nicht gemessen werden müssen. Es genügt, ihre isotopische Zusammensetzung zu kennen. Für die Berechungen mit der bulk-aerodynamischen Methode wurde ein Computerprogamm verwendet, das die unterschiedlichen atmosphärischen Schichtungen berücksichtigt. Die Energiebilanz des Sees wurde mit Hilfe der kurz- und langwelligen Strahlung, der gespeicherten Energie im See und der durch Zuflüsse und Niederschlag zugeführten Energie bestimmt. Die Messungen wurden auf einer kleiner Insel und an einem Mast in der Mitte des Sees durchgeführt. Die Verdunstung reichte von -1.1 mmd-1 bis 5.0 mmd-1 während der Sommermonate 1995. Die Ergebnisse der Energiebilanz stimmten gut mit den Ergebnissen der bulk-aerodynamischen Methode überein. Die Ergebnisse der Isotopenmethode stimmten relativ gut mit den Ergebnissen der beiden anderen Methoden überein, mit Ausnahme einiger Perioden. Es wurde festgestellt, daß sowohl die Isotopenmethode als auch die Energiebilanzmethode sensibel auf Fehler im Seevolumen reagieren. Beide Methoden enthalten einige Unsicherheiten wegen ihrer Abhängikeit von Wasserbilanzkomponenten, die z.T. schwer zu bestimmen sind. Die bulk-aerodynamische Methode dagegen ist unabhängig von der Wasserbilanz des Sees. Gute Ergebnisse können mit nur vier zu messenden Variablen erreicht werden (Windgeschwindigkeit, relative Luftfeuchtigkeit, Wasseroberflächen- und Lufttemperatur).<br><p>Parts of the thesis work later published as:</p><p>Saxena, R., Jaedicke, C., & Lundin, L. C. (1999). Comparison of lake evaporation estimated by isotope mass-balance, bulk-aerodynamic and bowen ratio methods. <em>Phys. Chem Earth (B), </em>Vol. 24, No. 7, pp. 851–859.</p><p>and</p><p>Saxena, R., & Jaedicke, C. (1997). Estimation of vapour flux from a shallow lake by oxygen -18 mass balance. <em>Isotope Techniques in the Study of Environmental Change</em>, 225–237. Vienna: IAEA-SM-349/23.</p>
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Eilers, V. H. M. "The estimation of groundwater recharge by soil water balance in semi-arid regions." Thesis, Cranfield University, 2002. http://dspace.lib.cranfield.ac.uk/handle/1826/4215.
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Quantification of groundwater recharge is a crucial prerequisite for sustainable groundwater resource management, particularly in semi-arid areas where there are large demands for groundwater supplies. This research presents an alternative approach for recharge estimation based on the soil water balance technique. The purpose is to develop a model which provides a suitable balance between physical credibility and data which realistically can be gathered. A spreadsheet model was written based on the conceptual representation of the principal physical processes which actually affect recharge in a semi-arid area. Alternative procedures were included in order to represent: (a) the estimation of runoff, (b) the inclusion of the period with predominant bare soil evaporation and (c) the accounting for evapotranspiration following rainfall on dry soil. The model was tested using real data from a semi-arid region (Northeast Nigeria) making use of selected periods of days and years in order to illustrate the principal model characteristics. The results were presented in the form of diagrams and graphs helping to visualise the interactions between the physical components and the effect of the additional procedures on recharge estimation. The credibility of the model was investigated using an alternative concept of 'analysis of plausibility'. This concept makes use of as wide as possible a range of quantitative and qualitative information from the hydrological system in order to verify the robustness of the model when extensive datasets required by conventional validation techniques are not available. The results suggested that the modelled recharge is physically sound and it is in line with the overall determination of recharge in semi-arid areas by a range of methods. The soil water balance model was utilised to explore important aspects of recharge in semi-arid regions showing the effect of the field variability on the model's output. The preliminary results show that the developed concept reasonably represents the inherent field variability, thus corroborating the strength of the approach for recharge estimation in semi-arid regions.
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Runeskog, Henrik. "Continuous Balance Evaluation by Image Analysis of Live Video : Fall Prevention Through Pose Estimation." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-297541.
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The deep learning technique Human Pose Estimation (or Human Keypoint Detection) is a promising field in tracking a person and identifying its posture. As posture and balance are two closely related concepts, the use of human pose estimation could be applied to fall prevention. By deriving the location of a persons Center of Mass and thereafter its Center of Pressure, one can evaluate the balance of a person without the use of force plates or sensors and solely using cameras. In this study, a human pose estimation model together with a predefined human weight distribution model were used to extract the location of a persons Center of Pressure in real time. The proposed method utilized two different methods of acquiring depth information from the frames - stereoscopy through two RGB-cameras and with the use of one RGB-depth camera. The estimated location of the Center of Pressure were compared to the location of the same parameter extracted while using the force plate Wii Balance Board. As the proposed method were to operate in real-time and without the use of computational processor enhancement, the choice of human pose estimation model were aimed to maximize software input/output speed. Thus, three models were used - one smaller and faster model called Lightweight Pose Network, one larger and accurate model called High-Resolution Network and one model placing itself somewhere in between the two other models, namely Pose Residual Network. The proposed method showed promising results for a real-time method of acquiring balance parameters. Although the largest source of error were the acquisition of depth information from the cameras. The results also showed that using a smaller and faster human pose estimation model proved to be sufficient in relation to the larger more accurate models in real-time usage and without the use of computational processor enhancement.<br>Djupinlärningstekniken Kroppshållningsestimation är ett lovande medel gällande att följa en person och identifiera dess kroppshållning. Eftersom kroppshållning och balans är två närliggande koncept, kan användning av kroppshållningsestimation appliceras till fallprevention. Genom att härleda läget för en persons tyngdpunkt och därefter läget för dess tryckcentrum, kan utvärdering en persons balans genomföras utan att använda kraftplattor eller sensorer och att enbart använda kameror. I denna studie har en kroppshållningsestimationmodell tillsammans med en fördefinierad kroppsviktfördelning använts för att extrahera läget för en persons tryckcentrum i realtid. Den föreslagna metoden använder två olika metoder för att utvinna djupseende av bilderna från kameror - stereoskopi genom användning av två RGB-kameror eller genom användning av en RGB-djupseende kamera. Det estimerade läget av tryckcentrat jämfördes med läget av samma parameter utvunnet genom användning av tryckplattan Wii Balance Board. Eftersom den föreslagna metoden var ämnad att fungera i realtid och utan hjälp av en GPU, blev valet av kroppshållningsestimationsmodellen inriktat på att maximera mjukvaruhastighet. Därför användes tre olika modeller - en mindre och snabbare modell vid namn Lightweight Pose Network, en större och mer träffsäker modell vid namn High-Resolution Network och en model som placerar sig någonstans mitt emellan de två andra modellerna gällande snabbhet och träffsäkerhet vid namn Pose Resolution Network. Den föreslagna metoden visade lovande resultat för utvinning av balansparametrar i realtid, fastän den största felfaktorn visade sig vara djupseendetekniken. Resultaten visade att användning av en mindre och snabbare kroppshållningsestimationsmodellen påvisar att hålla måttet i jämförelse med större och mer träffsäkra modeller vid användning i realtid och utan användning av externa dataprocessorer.
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Sun, Xianfeng. "A water balance approach to groundwater recharge estimation in Montagu area of the Western Klein Karoo." Thesis, University of the Western Cape, 2005. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=init_4142_1178702615.
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This aim of this study was to improve the understanding and functioning of the Table Mountain Group aquifer system and contribute to the sustainable development of this potential source for water supply in the Montagu area.
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Farhadi, Leila. "Estimation of land surface water and energy balance flux components and closure relation using conditional sampling." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/70757.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2012.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 348-364).<br>Models of terrestrial water and energy balance include numerical treatment of heat and moisture diffusion in the soil-vegetation-atmosphere continuum. These two diffusion and exchange processes are linked only at a few critical points. The performance and sensitivity of models are highly dependent on the nature of these linkages that are expressed as the closure function between heat and moisture dynamics. Land response to radiative forcing and partitioning of available energy into sensible and latent heat fluxes are dependant on the functional form. Since the function affects the surface fluxes, the influence reaches through the boundary layer and affects the lower atmosphere weather. As important as these closure functions are, they remain essentially empirical and untested across diverse conditions. It is critically important to develop observation-driven estimation procedures for the terrestrial water and energy closure problem, especially at the scale of modeling and with global coverage. In this dissertation a new approach to the estimation of key unknown parameters of water and energy balance equation and their closure relationship is introduced. This approach is based on averaging of heat and moisture diffusion equations conditioned on land surface temperature and moisture states respectively. The method is derived only from statistical stationarity and conservation statements of water and energy and thus it is scale free. The aim of this dissertation is to establish the theoretical basis for the approach and perform a global test using multi-platform remote sensing measurements. The feasibility of this approach is demonstrated at point-scale using synthetic data and flux-tower field site data. The method is applied to the mesoscale region of Gourma (West Africa) using multi-platform remote sensing data. The retrievals were verified against tower-flux field site data and physiographic characteristics of the region. The approach is used to find the functional form of the Evaporative Fraction (ratio of latent heat flux to sum of latent and sensible heat fluxes) dependence on soil moisture. Evaporative Fraction is a key closure function for surface and subsurface heat and moisture dynamics. With remote sensing data the dependence of this function on governing soil and vegetation characteristics is established.<br>by Leila Farhadi.<br>Ph.D.
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McCoy, Kurt J. "Estimation of vertical infiltration into deep Pittsburgh coal mines of WV-PA a fluid mass balance approach /." Morgantown, W. Va. : [West Virginia University Libraries], 2002. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=2745.
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Thesis (M.S.)--West Virginia University, 2002.<br>Title from document title page. Document formatted into pages; contains x, 150 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 87-90).
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Sun, Jian. "Parameter estimation of coupled water and energy balance models based on stationarity constraints of soil moisture and temperature." Thesis, Boston University, 2012. https://hdl.handle.net/2144/31613.
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Thesis (Ph.D.)--Boston University<br>PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.<br>A new method is developed for estimating the parameters of land surface water and energy balance models through enforcement of stationary constraints on soil moisture and temperature. Through conditional averaging of the water balance equation with respect to soil moisture and the energy balance equation with respect to surface temperature, a measure of stationarity is derived that approximates the errors present in predicted fluxes (e.g. evaporation, runoff, sensible heat, ground conduction) in terms of measured model inputs (e.g. precipitation, radiation, soil moisture and temperature). Minimization of the approximated error yields estimates of model parameters. The approach is distinct from traditional model calibration because the minimized error term does not depend on measurements of the predicted fluxes.
This proposed method is applied to a land surface water and energy balance model similar to those used in global climate models. The approach is tested at two Ameriflux sites with continuous in-situ measurements of soil moisture, temperature, radiation, and surface turbulent fluxes (evapotranspiration and sensible heat). Fluxes estimated with the proposed method match field measurements approximately as well as those estimated by traditional calibration. Replacing the in-situ land surface temperature and soil moisture with estimates retrieved from satellite leads to minimal degradation of model performance. Sensitivity analysis at these sites demonstrates that increasing model complexity does not improve performance.
With promising results from testing the approach at these field sites, the method is applied to estimate evapotranspiration over the Southern Great Plains region of North America. In this test, archived meteorological data and remotely sensed moisture and temperature are used to force the model. The spatial pattern of estimated mean annual evapotranspiration is in good agreement (RMSE of 8 Wm-2 , R 2 of 0.75) with published estimates derived from measured precipitation and streamflow. Estimated parameters are reasonably distributed and consistent with climate and vegetation patterns over the region.
Because there are so few sites on earth where surface turbulent fluxes are measured, the proposed approach is more widely applicable than traditional calibration methods, and thus could be used, with satellite data, to estimate maps of land surface parameters required by global climate models.<br>2031-01-01
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Krämer, Stefan [Verfasser]. "Heat Balance Calorimetry and Multirate State Estimation Applied to Semi-Batch Emulsion Copolymerisation to Achieve Optimal Control / Stefan Krämer." Aachen : Shaker, 2005. http://d-nb.info/1186588918/34.
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Möller, Jason John. "The use of remote sensing for soil moisture estimation using downscaling and soil water balance modelling in Malmesbury and the Riebeek Valley." Thesis, University of the Western Cape, 2014. http://hdl.handle.net/11394/4105.
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>Magister Scientiae - MSc<br>Soil moisture forms an integral part of the hydrological cycle and exerts considerable influence on hydrological processes at or near the earth’s surface. Knowledge of soil moisture is important for planning and decision-making in the agricultural sector, land and water conservation and flood warning. Point measurements of soil moisture, although highly accurate, are time consuming, costly and do not provide an accurate indication of the soil moisture variation over time and space as soil moisture has a high degree of spatial and temporal variability. The spatial variability of soil moisture is due to the heterogeneity of soil water holding properties, the influence of plants, and land uses. The downscaling of satellite microwave soil moisture estimates and soil water balance modelling was investigated at six transects in the semi-arid, Western Cape Province of South Africa, as alternatives to in situ soil measurements. It was found that microwave soil moisture estimates compared well to in situ measurements at the six transects (study sites), with coefficient of determination (r2) values greater than 0.7 and root mean square error (RMSE) values less than 1.5%. Downscaling using the universal triangle method, performed well at 4 of the 6 transects, with r2 values great than 0.65 and low to moderate RMSE values (0.5-12%). Soil water balance modelling similarly performed well in comparison with in situ measurements at 4 of the transects with regards to r2 values (>0.6) but had moderate to high RMSE (4.5-19%). Poor downscaling results were attributed to fine scale (within 1 km) surface heterogeneity while poor model performance was attributed to soil hydrological and rainfall heterogeneity within the study areas.
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Guerrero, José-Luis. "Robust Water Balance Modeling with Uncertain Discharge and Precipitation Data : Computational Geometry as a New Tool." Doctoral thesis, Uppsala universitet, Luft-, vatten och landskapslära, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-190686.
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Models are important tools for understanding the hydrological processes that govern water transport in the landscape and for prediction at times and places where no observations are available. The degree of trust placed on models, however, should not exceed the quality of the data they are fed with. The overall aim of this thesis was to tune the modeling process to account for the uncertainty in the data, by identifying robust parameter values using methods from computational geometry. The methods were developed and tested on data from the Choluteca River basin in Honduras. Quality control of precipitation and discharge data resulted in a rejection of 22% percent of daily raingage data and the complete removal of one out of the seven discharge stations analyzed. The raingage network was not found sufficient to capture the spatial and temporal variability of precipitation in the Choluteca River basin. The temporal variability of discharge was evaluated through a Monte Carlo assessment of the rating-equation parameter values over a moving time window of stage-discharge measurements. Al hydrometric stations showed considerable temporal variability in the stage-discharge relationship, which was largest for low flows, albeit with no common trend. The problem with limited data quality was addressed by identifying robust model parameter values within the set of well-performing (behavioral) parameter-value vectors with computational-geometry methods. The hypothesis that geometrically deep parameter-value vectors within the behavioral set were hydrologically robust was tested, and verified, using two depth functions. Deep parameter-value vectors tended to perform better than shallow ones, were less sensitive to small changes in their values, and were better suited to temporal transfer. Depth functions rank multidimensional data. Methods to visualize the multivariate distribution of behavioral parameters based on the ranked values were developed. It was shown that, by projecting along a common dimension, the multivariate distribution of behavioral parameters for models of varying complexity could be compared using the proposed visualization tools. This has a potential to aid in the selection of an adequate model structure considering the uncertainty in the data. These methods allowed to quantify observational uncertainties. Geometric methods have only recently begun to be used in hydrology. It was shown that they can be used to identify robust parameter values, and some of their potential uses were highlighted.<br>Modeller är viktiga verktyg för att förstå de hydrologiska processer som bestämmer vattnets transport i landskapet och för prognoser för tider och platser där det saknas mätdata. Graden av tillit till modeller bör emellertid inte överstiga kvaliteten på de data som de matas med. Det övergripande syftet med denna avhandling var att anpassa modelleringsprocessen så att den tar hänsyn till osäkerheten i data och identifierar robusta parametervärden med hjälp av metoder från beräkningsgeometrin. Metoderna var utvecklade och testades på data från Cholutecaflodens avrinningsområde i Honduras. Kvalitetskontrollen i nederbörds- och vattenföringsdata resulterade i att 22 % av de dagliga nederbördsobservationerna måste kasseras liksom alla data från en av sju analyserade vattenföringsstationer. Observationsnätet för nederbörd befanns otillräckligt för att fånga upp den rumsliga och tidsmässiga variabiliteten i den övre delen av Cholutecaflodens avrinningsområde. Vattenföringens tidsvariation utvärderades med en Monte Carlo-skattning av värdet på parametrarna i avbördningskurvan i ett rörligt tidsfönster av vattenföringsmätningar. Alla vattenföringsstationer uppvisade stor tidsvariation i avbördningskurvan som var störst för låga flöden, dock inte med någon gemensam trend. Problemet med den måttliga datakvaliteten bedömdes med hjälp av robusta modellparametervärden som identifierades med hjälp av beräkningsgeometriska metoder. Hypotesen att djupa parametervärdesuppsättningar var robusta testades och verifierades genom två djupfunktioner. Geometriskt djupa parametervärdesuppsättningar verkade ge bättre hydrologiska resultat än ytliga, var mindre känsliga för små ändringar i parametervärden och var bättre lämpade för förflyttning i tiden. Metoder utvecklades för att visualisera multivariata fördelningar av välpresterande parametrar baserade på de rangordnade värdena. Genom att projicera längs en gemensam dimension, kunde multivariata fördelningar av välpresterande parametrar hos modeller med varierande komplexitet jämföras med hjälp av det föreslagna visualiseringsverktyget. Det har alltså potentialen att bistå vid valet av en adekvat modellstruktur som tar hänsyn till osäkerheten i data. Dessa metoder möjliggjorde kvantifiering av observationsosäkerheter. Geometriska metoder har helt nyligen börjat användas inom hydrologin. I studien demonstrerades att de kan användas för att identifiera robusta parametervärdesuppsättningar och några av metodernas potentiella användningsområden belystes.
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Iwayama, Norihisa, Toru Shinzato, Shigeru Nakai, et al. "Quantitative estimation of dietary energy deficiency and effects of Its supplementation on protein nutritional status of nondiabetic uremic patients undergoing protein restricted dietary regimens." Nagoya University School of Medicine, 2001. http://hdl.handle.net/2237/5365.
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Nouri, Hamideh, Edward Glenn, Simon Beecham, et al. "Comparing Three Approaches of Evapotranspiration Estimation in Mixed Urban Vegetation: Field-Based, Remote Sensing-Based and Observational-Based Methods." MDPI AG, 2016. http://hdl.handle.net/10150/618720.
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Despite being the driest inhabited continent, Australia has one of the highest per capita water consumptions in the world. In addition, instead of having fit-for-purpose water supplies (using different qualities of water for different applications), highly treated drinking water is used for nearly all of Australia's urban water supply needs, including landscape irrigation. The water requirement of urban landscapes, particularly urban parklands, is of growing concern. The estimation of evapotranspiration (ET) and subsequently plant water requirements in urban vegetation needs to consider the heterogeneity of plants, soils, water, and climate characteristics. This research contributes to a broader effort to establish sustainable irrigation practices within the Adelaide Parklands in Adelaide, South Australia. In this paper, two practical ET estimation approaches are compared to a detailed Soil Water Balance (SWB) analysis over a one year period. One approach is the Water Use Classification of Landscape Plants (WUCOLS) method, which is based on expert opinion on the water needs of different classes of landscape plants. The other is a remote sensing approach based on the Enhanced Vegetation Index (EVI) from Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on the Terra satellite. Both methods require knowledge of reference ET calculated from meteorological data. The SWB determined that plants consumed 1084 mmyr(-1) of water in ET with an additional 16% lost to drainage past the root zone, an amount sufficient to keep salts from accumulating in the root zone. ET by MODIS EVI was 1088 mmyr(-1), very close to the SWB estimate, while WUCOLS estimated the total water requirement at only 802 mmyr(-1), 26% lower than the SWB estimate and 37% lower than the amount actually added including the drainage fraction. Individual monthly ET by MODIS was not accurate, but these errors were cancelled out to give good agreement on an annual time step. We conclude that the MODIS EVI method can provide accurate estimates of urban water requirements in mixed landscapes large enough to be sampled by MODIS imagery with 250-m resolution such as parklands and golf courses.
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Vallée, Pascal. "Estimation du risque de chute suite à une perturbation d’équilibre." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10261/document.
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Les chutes sont la deuxième cause de décès accidentels par traumatisme involontaire dans le monde. Les conséquences physiques et psychologiques représentent aussi un frein important à la mobilité des personnes âgées. Prévenir ces chutes apparait donc comme un enjeu majeur. Une première étape nécessaire est d'identifier les situations présentant un risque de chute important. L'objectif de cette thèse est de proposer des outils permettant de faire le lien entre une perturbation et le risque de chute associé. Dans une première partie, un modèle simple permet d'estimer les états à partir desquels il est possible de retourner dans une situation d'équilibre. Nous nous intéressons ensuite aux perturbations externes continues. Les résultats de la littérature étant limités sur cet aspect, une campagne expérimentale a été mise en place pour identifier les effets de certains paramètres de la perturbation sur le seuil de rattrapage. Le modèle est alors étendu pour traiter le cas de perturbations de l'équilibre ayant un profil temporel variable. Pour finir, nous proposons une modélisation utilisant un contrôleur basé sur la commande prédictive mettant en avant la régulation des stratégies de rattrapage. L'ensemble de ces travaux mettent en avant l'influence des paramètres liés au rattrapage qu'il est difficile d'appréhender lors d'expérimentations. Ils montrent également l'importance de la caractérisation de l'élément déclencheur de la perte d'équilibre dont la description est souvent incomplète dans la littérature. Certaines améliorations peuvent être apportées comme la représentation d'appuis non-coplanaires ou une intégration plus détaillée des aspects sensoriels<br>Falling is the second most important cause of accidental deaths in the world. These falls lead to physical injuries and psychological consequences which limit mobility especially for the elderly. Being able to prevent these events appears to be crucial and a first mandatory step is to identify the risk of fall depending on the situation (slipping, hazardous environment …). The objective of this thesis is to propose numerical tools in order to link the risk of fall to the balance perturbation. In a first part, a simple numerical model estimates if initial unbalanced states can be recovered using one recovery step. Then a focus was made on external perturbations with a specific temporal profile close to public transportation perturbations. An experimental protocol was set up due to the lack of knowledge about these perturbations. The experiment investigated the effect of the perturbation parameters on the Balance Recovery (BR) threshold. An adjustment of the previous model was made to evaluate continuous perturbations and to compare its results against our experimental findings. The final chapter developed a complementary approach based on previous work using a model predictive control scheme which aims to regulate BR strategies. This whole work contributes to highlight the BR parameters which are difficult to assess during experimental procedures. It also points out the perturbation definition which is frequently incomplete in the literature although it is the phenomenon responsible for the BR process. In order to represent more realistic human behaviors some improvements can be done such as adding noncoplanar contacts or as integrating more detailed sensorimotor aspects
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Dürr, Robert [Verfasser], Achim [Akademischer Betreuer] Kienle, and Dominique [Akademischer Betreuer] Thevenin. "Parameter estimation and method of moments for multi dimensional population balance equations with application to vaccine production processes / Robert Dürr ; Achim Kienle, Dominique Thévenin." Magdeburg : Universitätsbibliothek, 2016. http://d-nb.info/1123631476/34.
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Fersch, B. [Verfasser]. "Large scale water balance estimation from downscaled atmospheric moisture budgets and evaluation with global climatological data sets and the GRACE spaceborne gravimetry / B. Fersch." Karlsruhe : KIT-Bibliothek, 2012. http://d-nb.info/1199286753/34.
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Dworak, Jennifer Lynn. "Modeling defective part level due to static and dynamic defects based upon site observation and excitation balance." Diss., Texas A&M University, 2004. http://hdl.handle.net/1969.1/323.
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Manufacture testing of digital integrated circuits is essential for high quality. However, exhaustive testing is impractical, and only a small subset of all possible test patterns (or test pattern pairs) may be applied. Thus, it is crucial to choose a subset that detects a high percentage of the defective parts and produces a low defective part level. Historically, test pattern generation has often been seen as a deterministic endeavor. Test sets are generated to deterministically ensure that a large percentage of the targeted faults are detected. However, many real defects do not behave like these faults, and a test set that detects them all may still miss many defects. Unfortunately, modeling all possible defects as faults is impractical. Thus, it is important to fortuitously detect unmodeled defects using high quality test sets. To maximize fortuitous detection, we do not assume a high correlation between faults and actual defects. Instead, we look at the common requirements for all defect detection. We deterministically maximize the observations of the leastobserved sites while randomly exciting the defects that may be present. The resulting decrease in defective part level is estimated using the MPGD model. This dissertation describes the MPGD defective part level model and shows how it can be used to predict defective part levels resulting from static defect detection. Unlike many other predictors, its predictions are a function of site observations, not fault coverage, and thus it is generally more accurate at high fault coverages. Furthermore, its components model the physical realities of site observation and defect excitation, and thus it can be used to give insight into better test generation strategies. Next, we investigate the effect of additional constraints on the fortuitous detection of defects-specifically, as we focus on detecting dynamic defects instead of static ones. We show that the quality of the randomness of excitation becomes increasingly important as defect complexity increases. We introduce a new metric, called excitation balance, to estimate the quality of the excitation, and we show how excitation balance relates to the constant τ in the MPGD model.
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Fersch, Benjamin [Verfasser], and Harald [Akademischer Betreuer] Kunstmann. "Large scale water balance estimation from downscaled atmospheric moisture budgets and evaluation with global climatological data sets and the GRACE spaceborne gravimetry / Benjamin Fersch. Betreuer: Harald Kunstmann." Augsburg : Universität Augsburg, 2012. http://d-nb.info/1077700970/34.
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Li, Huayu. "Process measurements and kinetics of unseeded batch cooling crystallization." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53503.
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This thesis describes the development of an empirical model of focus beam reflectance measurements (FBRM) and the application of the model to monitoring batch cooling crystallization and extracting information on crystallization kinetics.
Batch crystallization is widely used in the fine chemical and pharmaceutical industries to purify and separate solid products. The crystal size distribution (CSD) of the final product greatly influences the product characteristics, such as purity, stability, and bioavailability. It also has a great effect on downstream processing. To achieve a desired CSD of the final product, batch crystallization processes need to be monitored, understood, and controlled.
FBRM is a promising technique for in situ determination of the CSD. It is based on scattering of laser light and provides a chord-length distribution (CLD), which is a complex function of crystal geometry. In this thesis, an empirical correlation between CSDs and CLDs is established and applied in place of existing first-principles FBRM models. Built from experimental data, the empirical mapping of CSD and CLD is advantageous in representing some effects that are difficult to quantify by mathematical and physical expressions. The developed model enables computation of the CSD from measured CLDs, which can be followed during the evolution of the crystal population during batch cooling crystallization processes.
Paracetamol, a common drug product also known as acetaminophen, is selected as the model compound in this thesis study. The empirical model was first established and verified in a paracetamol-nonsolvent (toluene) slurry, and later applied to the paracetamol-ethanol crystallization system. Complementary to the FBRM measurements, solute concentrations in the liquid phase were determined by in situ infrared spectra, and they were jointly implemented to monitor the crystallization process.
The framework of measuring the CSD and the solute concentration allows the estimation of crystallization kinetics, including those for primary nucleation, secondary nucleation, and crystal growth. These parameters were determined simultaneously by fitting the full population balance model to process measurements obtained from multiple unseeded paracetamol-ethanol crystallization runs.
The major contributions of this thesis study are (1) providing a novel methodology for using FBRM measurements to estimate CSD; (2) development of an experimental protocol that provided data sets rich in information on crystal growth and primary and secondary nucleation; (3) interpretation of kinetics so that appropriate model parameters could be extracted from fitting population balances to experimental data; (4) identification of the potential importance of secondary nucleation relative to primary nucleation. The protocol and methods developed in this study can be applied to other systems for evaluating and improving batch crystallization processes.
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Chata, Florent. "Estimation par méthodes inverses des profils d’émission des machines à bois électroportatives." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0161/document.
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Cette thèse est dédiée à l'estimation de l'intensité d'une source de polluant de type particulaire par inversion de signaux de concentration mesurés avec un nombre fini de capteurs placés loin de la source. Cette méthode d'estimation inclut deux étapes distinctes. La première étape consiste à déterminer les paramètres du modèle d'inversion en utilisant une source d'aérosol connue et les mesures de concentration en particules correspondantes. Dans une seconde étape, une source d'aérosol inconnue est reconstruite à partir de l'inversion du modèle et des mesures de la concentration. Ce manuscrit traite dans un premier temps du cas stationnaire. L'approche théorique exposée permet de proposer un placement optimal des capteurs en plus de la méthode d'estimation de la source. Dans un second temps, on considère le cas où la source inconnue d'aérosol est instationnaire. La méthode d'estimation repose sur une approche convolutive du système, en introduisant la notion d'impédance source/capteur. Après une présentation de la technique d'inversion propre à la méthode d'estimation, elle est appliquée expérimentalement au cas des machines à bois éléctroportatives, dans le but de les discriminer en fonction de leur caractère émissif<br>This thesis is dedicated to the determination of unknown aerosol sources emission profiles from aerosol concentration measurements in the far-field. This procedure includes two distinct steps. The first step consists in determining the model linking the aerosol source and the concentration measurements using a known source of aerosols and the corresponding dust measurements. In a second step, the unknown source of aerosols is reconstructed by inverting the model for the measured aerosol concentrations. This manuscript deals in a first time with the stationary case. The exposed theoretical approach allows to suggest an optimal sensors placement in addition to the source estimation method. In a second time, we consider the case where the unknown aerosol source is unsteady. The estimation method is then based on a convolutive system approach, introducing the concept of source/sensor impedance. After a presentation of the numerical inversion technique, the method is applied experimentally to the real case of hand-held wood working machines so as to classify the machines with respect to their emission rate
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Khedekar, Mayur. "Temperature Based Estimation of the Time-Resolved Massflux of ICE Exhaust Gas Flow." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-300050.
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The aim ofthe study was to provideinformation and experience gained with fine wire thermocouples (TCs)or resistance wire thermometers (RWTs) temperature signals to estimate the timeresolved heat transfercoefficient. Constant current method was assumed in the study and medium used in this study was air. Here the heat balance equation has been described, different Nucorrelations and further discusses potential hurdles and difficulties one may encounter while calculating heat transfer coefficient. As asolution, the use of an appropriate heatbalance equation and lowpass filter was suggested as this provides a more accurate fitting. The investigation was carried out for Reynolds number (Re) 103 to 107 and Prandlt number (Pr) 0.734. The impact of the Re and Pr on the Nusselts number (Nu) around a cylinder was represented and all the results were compared with GT-POWER engine simulation software.<br>Syftet med studien var att tillhandahålla information och erfarenhet från fina trådtermoelement (TC) eller motståndstrådstermometrar (RWT) temperatursignaler för att uppskatta den tidsupplösta värmeöverföringskoefficienten. Metoden med konstant flöde antogs i studien och mediet som användes i denna studie var luft. Här har värmebalansekvationen beskrivits, olika Nu-korrelationer och diskuterat ytterligare potentiella hinder och svårigheter man kan stöta på vid beräkning av värmeöverföringskoefficienten. Som en lösning föreslogs användning av en lämplig värmebalansekvation och lågpassfilter eftersom detta ger en mer exaktpassform. Undersökningen genomfördes för Reynoldsnummer (Re) 103 till 107 och Prandlt nummer (Pr) 0,734. Effekten av Re och Pr på Nusselts-numret (Nu) runt en cylinder representerades och alla resultat jämfördes med GT-POWER-motorns simuleringsprogram.
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Magnevall, Martin. "Methods for Simulation and Characterization of Nonlinear Mechanical Structures." Licentiate thesis, Karlskrona : Blekinge Institute of Technology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-00430.
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Trial and error and the use of highly time-consuming methods are often necessary for modeling, simulating and characterizing nonlinear dynamical systems. However, for the rather common special case when a nonlinear system has linear relations between many of its degrees of freedom there are particularly interesting opportunities for more efficient approaches. The aim of this thesis is to develop and validate new efficient methods for the theoretical and experimental study of mechanical systems that include significant zero-memory or hysteretic nonlinearities related to only small parts of the whole system. The basic idea is to take advantage of the fact that most of the system is linear and to use much of the linear theories behind forced response simulations. This is made possible by modeling the nonlinearities as external forces acting on the underlying linear system. The result is very fast simulation routines where the model is based on the residues and poles of the underlying linear system. These residues and poles can be obtained analytically, from finite element models or from experimental measurements, making these forced response routines very versatile. Using this approach, a complete nonlinear model contains both linear and nonlinear parts. Thus, it is also important to have robust and accurate methods for estimating both the linear and nonlinear system parameters from experimental data. The results of this work include robust and user-friendly routines based on sinusoidal and random noise excitation signals for characterization and description of nonlinearities from experimental measurements. These routines are used to create models of the studied systems. When combined with efficient simulation routines, complete tools are created which are both versatile and computationally inexpensive. The developed methods have been tested both by simulations and with experimental test rigs with promising results. This indicates that they are useful in practice and can provide a basis for future research and development of methods capable of handling more complex nonlinear systems.
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Ameline, Maël. "Diagnostic hydrique et estimation de la production de la culture de maïs : vers la mise en place d'un service tout temps." Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30314.
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La thèse répond aux objectifs d'évaluer le potentiel d'estimation de la production de parcelles de maïs, ainsi que de leurs besoins hydriques. Les travaux, validés dans le Sud-Ouest de la France, reposent sur le couplage du modèle agro-météorologique à de l'imagerie satellitaire pour étendre le suivi à une échelle régionale. Le but est de s'affranchir des contraintes nuageuses imposées sur les acquisitions optiques, grâce à l'utilisation du radar Sentinel-1. L'estimation de la production comprend la biomasse sèche (épi, plante) ainsi que le rendement à l'échelle parcellaire. Au-delà des améliorations du modèle, l'assimilation combinée de l'optique et du radar donne de bons résultats et améliore les simulations basées sur l'optique en comblant l'absence de données en début de saison (forte nébulosité). Les résultats de l'estimation du contenu en eau sont plus contrastés. Le détail des erreurs révèle notamment des défauts liés aux propriétés du sol ou aux déclarations des agriculteurs<br>The study explores the feasibility to estimate the corn field production and its water needs during the irrigation period. The work, validated in the South-West of France, is based on an agro-meteorological model coupled with satellite imagery to extend monitoring to regional scale. The recent availability of Sentinel-1 radar mission allows monitoring without atmospheric constraints (e.g. clouds) as opposed to optical acquisitions. The estimation of production is linked with dry biomass (ear, plant) and yield data at the field scale. Beyond new improvements, the combination of optical and radar provides accurate results and even improves the estimations based on optical by filling the gaps caused by cloud cover at the beginning of the season. The water needs simulation are more contrasted as a result of the accuracy of the input data. Moreover, some features (e.g. soil properties) can be seen within soil moisture measurements, even though they cannot be modeled
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Janyene, Abderrahmane. "Validation de données des systèmes dynamiques linéaires." Nancy 1, 1987. http://www.theses.fr/1987NAN10190.
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Étude d'une méthode de validation de données dans les unités de production industrielle dont le fonctionnement est caractérisé par des systèmes dynamiques linéaires, ceci en présence de toutes les mesures de grandeurs, dans un 1**(ER) temps, et avec des mesures manquantes, ensuite
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Battude, Marjorie. "Estimation des rendements, des besoins et consommations en eau du maïs dans le sud-ouest de la France : apport de la télédétection à hautes résolutions spatiale et temporelle." Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30037/document.
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Le travail de cette thèse s'inscrit dans le cadre du projet MAISEO qui associe, entre autres partenaires, la CACG, gestionnaire de l'eau sur des bassins hydrographiques du Sud-Ouest, Météo-France et le CESBIO. Un des objectifs est de proposer des méthodes innovantes et opérationnelles pour l'estimation des besoins en eau des cultures à l'échelle d'un territoire. Il s'agit de fournir au gestionnaire des outils qui lui permettront de mieux gérer la demande en eau d'irrigation liée à la culture dominante présente dans le Sud-Ouest de la France: le maïs. L'objectif de la thèse consistait à estimer les rendements et les besoins en eau du maïs sur de grandes surfaces. Pour cela, nous avons utilisé un modèle agro-météorologique couplé à l'imagerie satellitaire optique. De nombreuses images à haute résolution spatiale et temporelle provenant de différents capteurs ont été utilisées, préfigurant l'arrivée des données Sentinel-2 lancé en 2015. Il s'agissait dans un premier temps de coupler les données satellitaires avec le modèle SAFY (Simple Algorithm For Yield estimates, Duchemin et al., 2008a), qui simule le développement des plantes en se basant sur la théorie des efficiences (Monteith, 1972), afin d'estimer la biomasse et le rendement du maïs. De nombreuses données terrain ont permis de valider les sorties du modèle. A l'échelle régionale, les résultats ont été agrégés et comparés aux statistiques départementales Agreste. Les résultats ont conduit à proposer une nouvelle version du modèle SAFY permettant de prendre en compte la variation temporelle de l'efficience de conversion de la lumière effective (ELUE) et de la surface spécifique foliaire (SLA). Cette modification permet une meilleure prise en compte de la dynamique de croissance de la végétation et une amélioration de l'estimation du rendement tant à l'échelle locale que régionale. La méthode de calibration a également été améliorée afin de limiter le recours aux données in situ difficilement accessibles sur de grandes surfaces. Nous avons pu mettre en évidence l'apport de la double logistique, utilisée pour interpoler les profils temporels de NDVI. Cette interpolation a permis d'affiner la délimitation du cycle cultural et de contraindre plus précisément certains paramètres du modèle comme la date de levée. Une fois contraint par les données satellitaires, le modèle SAFY est capable de reproduire les rendements sur les deux départements avec une bonne précision et ce sans prendre en compte l'évolution du stock d'eau dans le sol (Battude et al., 2016)<br>This Ph.D. thesis is part of the MAISEO project associating partners among them: the CACG, managing the water supply of several watersheds located in the south west of France, the Meteo-France center and the CESBIO. One of the goals is to develop innovative and operational tools to estimate crops' water needs at the territory scale. The aim is to provide managers tools to better manage the water supplies linked to the predominant crop encountered in south west of France: maize. The objective of the thesis was to estimate the yield and water requirements of maize crop over large areas. For this purpose, we used an agro-meteorological model coupled to optical satellite imagery. Numerous high spatial and temporal resolution images from different sensors have been used, prefiguring the arrival of the Sentinel-2 data launched in 2015. The first part was to combine remote sensing data with the SAFY (Simple Algorithm For Yield estimates) crop model (Duchemin et al., 2008a) that simulates plant development based on Monteith theory (Monteith, 1972) in order to accurately estimate maize biomass and yield. Numerous field data have been used for the validation at local scale. At regional scale, the results have been aggregated and compared to Agreste yield statistics provided by the French government. Results led us to propose a new formulation of the SAFY model taking into account the temporal variation of the effective light use efficiency (ELUE) and of the specific leaf area (SLA). This modification allows a better simulation of the crop growth dynamics and an improvement of yield estimates at the local and regional scale. Furthermore, we changed the calibration method in order to limit the use of in situ data that are difficult to access over large areas. We also highlighted the contribution of the double logistic function, used to interpolate the NDVI time series. This interpolation enables an accurate determination of the crop growing season and it allows constraining some model parameters such as the emergence date. The SAFY model constrained by remote sensing data is able to well reproduce the yield for the two departments without taking into account the evolution of the soil water storage (Battude et al., 2016)
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Saadi, Sameh. "Estimation spatialisée de l'évapotranspiration réelle et des volumes d'irrigation à l'aide de modèles de bilans hydrique et énergétique forcés par des données de la télédétection optique (VIS/PIR/IRT)." Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30008/document.
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La gestion efficace de l'eau dans les régions arides et semi-arides est un problème majeur, principalement dans les zones irriguées. La conception d'outils fournissant des estimations régionales des composantes du bilan hydrique peut aider à la gestion durable de la ressource en eau dans ces régions. La télédétection multi-capteurs a démontré un très fort potentiel pour le suivi des ressources hydriques agricoles à différentes échelles. Cette thèse vise à développer des techniques et des méthodes efficaces pour estimer les variables hydrologiques (évapotranspiration et les volumes d'irrigation) afin d'évaluer, dans l'espace (résolutions "métrique" et "kilométrique"), les besoins en eau des cultures du couvert végétal de la plaine de Kairouan (Tunisie centrale) ainsi que les volumes d'irrigation extraits de son aquifère surexploité. L'approche adoptée combine l'expérimentation, la modélisation et l'utilisation de données de télédétection multi-capteurs / multi-résolutions. Les deux types d'outils utilisés sont le modèle de bilan hydrique SAMIR et le modèle de bilan d'énergie SPARSE. Les variables estimées par SAMIR et SPARSE sont évaluées à l'aide des mesures terrain (mesures d'un scintillomètre XLAS) et des enquêtes de terrain (volumes d'irrigation observés). Les volumes d'irrigation saisonniers estimés par SAMIR sont acceptables, même si les résultats à des échelles de temps plus fines (mensuelles) doivent être améliorés. Ainsi, les paramètres de SAMIR, en particulier les paramètres non calibrés, sont revisités afin d'améliorer les performances de simulation de l'ET et des volumes d'irrigation. Les estimations des flux de chaleur sensible et latente par SPARSE sont en étroit accord avec celles obtenues à partir du XLAS. Cependant, l'extrapolation de l'évapotranspiration instantanée au pas de temps journalier est moins évidente<br>In arid and semi-arid regions, efficient agricultural water management is a major issue, mainly in irrigated areas. The design of tools that provide an estimate of water balance components at the regional scale may help sustainable management of limited water resources in the water scarce regions. Remotely sensed Earth observation has become a major research field for agricultural water resources management. The main objective of this thesis is to develop and test efficient techniques and methods to estimate hydrological variables (Evapotranspiration (ET) and irrigation volumes) in order to assess, at "metric" and "kilometric" resolution , the crop water requirements and the extracted irrigation volumes in the Kairouan plain (central Tunisia). The adopted approach combines field experimentation, modeling and the use of multi-sensor / multi-resolution remote sensing data. Two modeling tools are used: the soil water balance model SAMIR and the energy balance model, SPARSE. SAMIR and SPARSE estimates are assessed using field measurements (Scintillometer XLAS measurements) and field surveys (observed irrigation volumes). The seasonal irrigation volumes estimated by the SAMIR model are acceptable, even though results at finer timescales (monthly and below) needed to be improved. Hence, the SAMIR model parameters, especially the uncalibrated ones are revisited in order to improve the results. SPARSE estimates of sensible and latent heat ?uxes are in close agreement with those obtained from the XLAS. However, the extrapolation from instantaneous to daily ET is less obvious
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Pinjuv, Guy L. "Hybrid forest modelling of Pinus Radiata D. Don in Canterbury, New Zealand." Thesis, University of Canterbury. New Zealand School of Forestry, 2006. http://hdl.handle.net/10092/1102.
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During this study two models were developed to predict growth of Pinus radiata D.Don plantations in Canterbury, New Zealand. The first, CanSPBL(1.2), is a model for whole rotations of stands owned by Selwyn Plantation Limited in Canterbury. The second model, CanSPBL(water) is a hybrid growth model for the Selwyn estate in Canterbury that incorporates an index of root zone water balance over the simulation period. An existing stand growth and yield model CanSPBL was examined using a validation dataset of PSP measurements that were not used in model fitting. Projection bias was shown for mean top height, basal area per hectare, and residual stand stocking particularly for stands at elevations exceeding 450 metres. The new model, CanSPBL(1.2) showed an increase in precision of 4 - 46% over CanSPBL(1.0) at a stand level. The components of the stand model include mean top height, basal area per hectare, stems per hectare, and diameter distribution. The mortality model was made in conjunction with managers at CanSPBL to exclude catastrophic mortality events from model projections. Data used for model fitting was filtered using a mortality index based on the -3/2 power law. An examination of this model with an independent dataset showed little apparent bias. The new model, CanSPBL(water) was developed to include an index of water balance over the simulation period. Water balance estimates were made using a sub model for root zone water balance included in the hybrid physiological model 3-PG (Landsberg and Waring, 1997). The new model showed an increase in precision of 1 - 4% over CanSPBL(1.2) at a stand level (with the exception of the model for maximum diameter which showed a decrease in precision of 0.78%) using climatic inputs that included yearly variation. However the model showed increases of precision from 0.5 to 8% (with the exception of maximum diameter again, showing a decrease in precision of 0.13%) using long term monthly average climatic inputs. The components of the stand model also include mean top height, basal area per hectare, stems per hectare, and diameter distribution. The mortality model was also fitted with a data set filtered using a mortality severity index based on the -3/2 power law to exclude catastrophic mortality events. An examination of this model with an independent dataset showed little apparent bias. Two models to predict a one sided canopy leaf area index (LAI) of radiata pine stands in the Canterbury Plains of New Zealand were also developed. The models were fitted using non-linear least squares regression of LAI estimates against stem measurements and stand characteristics. LAI estimates were derived from digital analysis of fisheye lens photography. The models were kept simple to avoid computational circularity for physiological modelling applications. This study included an objective comparison and validation of a range of model types. The models CANTY (Goulding, 1995), CanSPBL(1.2) (Pinjuv, 2005), CanSPBL-water (Pinjuv, 2005), and 3-PG (Landsberg and Waring, 1997) were compared and validated with the main criteria for comparison being each model s ability to match actual historical measurements of forest growth in an independent data set. Overall, the models CanSPBL(water), and CanSPBL(1.2) performed the best in terms of basal area and mean top height prediction. Both models CanSPBL(water), and CanSPBL(1.2) showed a slightly worse fit in predictions of stocking than did the model CANTY. The hybrid model 3PG showed a better fit for the prediction of basal area than the statistically based model CANTY, but showed a worse fit for the prediction of final stocking than all other models. In terms of distribution of residuals, CanSPBL(1.2) had overall the lowest skewness, kurtosis, and all model parameters tested significant for normality. 3PG performed the worst on average, in terms of the distribution of residuals, and all models tested positively for the normality of residual distribution.
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Santos, Fabiano Barbosa dos. "Estimativa do balanço de energia utilizando imagens do sensor TM-Landsat 5 no baixo São Francisco." Universidade Federal de Alagoas, 2012. http://repositorio.ufal.br/handle/riufal/903.
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Remote sensing is a very effective way for obtaining earth surface information due to its wide area coverage and low cost. This paper aims to map and estimate the components of the Radiation Balance (Albedo, Normalized Difference Vegetation Index, Surface Temperature) and Energy Balance (Net Radiation, Soil Heat Flux, Sensible Heat Flux and Latent Heat Flux) through the sensor Thematic Mapper coupled to the Landsat-5, collected through the Instituto Nacional de Pesquisas Espaciais, combined with a digital elevation model with altitude information. The components were obtained from the Radiation and Energy Balance performed by the SEBAL/METRIC algorithm, with information obtained from two data collection platforms (Xingó-AL and Poço Redondo-SE). The covered region has an area of approximately 1342 square kilometers and includes the municipalities of Monteirópolis, Palestina, Pão de Açúcar, Piranhas and São José da Tapera, Alagoas, and the cities of Canindé do São Francisco, Poço Redondo and Porto da Folha in the state of Sergipe. The images collected corresponded to the passage of TM/Landsat-5 on said area at 9 h 30 min (Solar time) of October 17, 1999 (day 290 in the Julian calendar), October 06, 2001 (day 279 in Julian calendar) and December 7, 2006 (day 341 in the Julian calendar) in orbit 214 and point 67. The first parameter obtained, the albedo, has increased by approximately 3% in the surface over the seven years analyzed, caused due to loss in vegetation cover, analyzed by the NDVI, this loss led to an increase in surface temperature by about 4°C. Due to the large extent and depth of the Lower São Francisco which has ability to retain a lot of energy, the values of the radiation balance were more than to 675 W.m-2, and the areas with exposed soil were below the 475 W.m-2. The ground heat flux was increased gradually, ranging from about 10 W.m-2 in five years, with predominance of 96 W.m-2 on 07/12/2006. Sensible Heat Flux, a parameter to be very sensitive to rainfall, had an increase of 100 W.m-2 in the first two years and a decay of 50 W.m-2 in five years later. In regions without vegetation cover flow values sensible heat exceeded 630 W.m-2. The latent heat flux has values opposed to sensible heat flux in regions without vegetation cover, where the values obtained were under 70 W.m-2 and the São Francisco river values are above 630 W.m-2. The values suffered interference in the recorded rainfall values for the days prior to 17/10/1999 and 06/12/2006<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>O sensoriamento remoto é um meio bastante eficaz para obtenção de informações da superfície terrestre devido a sua grande área de cobertura e baixo custo. O presente trabalho visa mapear e estimar as componentes do Balanço de Radiação (albedo, Índice de Vegetação da Diferença Normalizada e Temperatura de Superfície) e do Balanço de Energia (Saldo de Radiação, Fluxo de Calor no Solo, Fluxo de Calor Sensível e Fluxo de Calor Latente) por meio de imagens do sensor Thematic Mapper a bordo do satélite Landsat 5, combinadas com um modelo de elevação digital com informações altimétricas. A obtenção dos componentes dos balanços de radiação e energia foi realizada por meio do algoritmo SEBAL/METRIC,complementadas com informações obtidas em duas plataformas de coleta de dados (Xingó-AL e Poço Redondo-SE). A região abordada tem uma área de aproximadamente 1342 Km² e contempla os municípios de Monteirópolis, Palestina, Pão de Açúcar, Piranhas e São José da Tapera no estado de Alagoas, e os municípios de Canindé de São Francisco, Poço Redondo e Porto da Folha no estado de Sergipe. As imagens coletadas correspondem à passagem do Landsat 5 sobre a referida área às 9 h 30 min. (tempo local) dos dias 17 de outubro de 1999, 06 de outubro de 2001 e 07 de dezembro de 2006 na órbita 214 e ponto 67. A primeira variável obtida, o albedo, sofreu um aumento de aproximadamente 3% na superfície terrestre ao longo dos sete anos analisados, ocasionado devido a perda na cobertura de vegetação, analisado por meio do IVDN. Essa perda acarretou um aumento na Temperatura de Superfície em cerca de 4ºC. Devido a grande extensão e profundidade do Baixo São Francisco, o qual tem capacidade de reter bastante energia, os valores do Saldo de Radiação foram superiores a 675W.m-2, e as áreas com solo exposto ficassem abaixo dos 475 W.m-2. O Fluxo de Calor no Solo sofreu um aumento gradativo, variando cerca de 10 W.m-2 nos cinco anos, com predominância de 96 W.m-2 em 07/12/2006. O Fluxo de Calor Sensível, por ser um parâmetro bastante sensível a precipitação pluviométrica, teve um aumento de 100 W.m-2 nos dois primeiros anos e um decaimento de 50 W.m-2 nos cinco anos posteriores. Em regiões sem cobertura de vegetação os valores do fluxo de calor sensível excederam os 630 W.m-2. O Fluxo de Calor Latente apresentou valores opostos ao fluxo de calor sensível, e nas regiões sem cobertura de vegetação foram obtidos valores abaixo de 70 W.m-2 e no leito do rio São Francisco os valores são acima de 630 W.m-2. Os valores obtidos sofreram interferência do registro de chuva, para os dias anteriores a 17/10/1999 e 06/12/2006
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Kilic, Lise. "Estimation des paramètres de surface des océans et de la banquise à partir d’observations micro-ondes basses fréquences." Electronic Thesis or Diss., Sorbonne université, 2019. http://www.theses.fr/2019SORUS167.
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Les océans et la banquise jouent un rôle important dans le système climatique et météorologique. Une future mission satellite en micro-ondes passives basses fréquences, conçue pour observer les régions polaires est actuellement à l’étude à l’Agence Spatiale Européenne pour l’expansion du programme Copernicus. Les observations satellites en micro-ondes passives permettent une observation de la surface de la Terre par tous temps, aussi bien de jour que de nuit. Dans cette thèse, nous nous intéressons à l’estimation des paramètres de surface de l’océan et de la banquise à partir des observations satellites micro-ondes passives basses fréquences. L’objectif est de développer de nouvelles méthodes d’estimation de ces paramètres qui soient plus efficaces et adaptées à la future mission satellite micro-onde passive CIMR (Copernicus Imaging Microwave Radiometer). La première partie de la thèse traite de l’estimation des paramètres océaniques tels que la température de la surface de la mer, la salinité et la vitesse du vent océanique. La deuxième partie traite de l’estimation des paramètres de la banquise tels que la concentration en glace, l’épaisseur de neige et la température d’interface neige-glace. Enfin, avec les méthodes développées dans cette thèse les performances de la mission CIMR sont évaluées et comparées à celles des missions actuelles<br>The oceans and sea ice play an important role in the climate and weather system. A future low-frequency passive microwave satellite mission designed to observe the polar regions is currently under study at the European Space Agency for the expansion of the Copernicus programme. Passive microwave satellite observations provide all-weather observation of the Earth surface, both day and night. In this thesis, we are interested in estimating ocean and ice surface parameters from low-frequency passive microwave satellite observations. The objective is to develop new methods for estimating these parameters that are more efficient and adapted to the future passive microwave satellite mission CIMR (Copernicus Imaging Microwave Radiometer). The first part of the thesis deals with the estimation of ocean parameters such as sea surface temperature, salinity and ocean wind speed. The second part deals with the estimation of sea ice parameters such as sea ice concentration, snow depth and snow-ice interface temperature. Finally, with the methods developed in this thesis, the performances of the CIMR mission are evaluated and compared with the current missions
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Fayolle, Jean. "Validation de données et diagnostic des procédés industriels." Nancy 1, 1987. http://www.theses.fr/1987NAN10171.
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Étude de la validation de données issues de procédés industriels en régime statique, décrits par un modèle strictement exact. Applications relatives à l'établissement de bilans matière statistiquement cohérents. Après une présentation générale du problème, le cas des systèmes linéaires est étudié. Différentes méthodes analytiques de validation peuvent être mises en œuvre. La structure des équations permet de développer des algorithmes récursifs originaux adaptés au traitement des grands systèmes. Pour les systèmes partiellement observés, une décomposition selon l'observabilité doit être conduite. Elle fournit une classification des variables et met en évidence les équations de redondance. Dans le cas des systèmes bilinéaires, la solution optimale est obtenue par des méthodes itératives. Un algorithme relaxé se révèle bien adapté au traitement des systèmes de grandes dimensions. Il exploite les récurrences dévelopées pour l'étude des systèmes linéaires et se généralise au cas n-linéaire. Pour les systèmes partiellement observés, une condition d'observabilité locale doit être vérifiée. La redondance d'information est mise à profit pour détecter et localiser des capteurs défaillants. Enfin, un logiciel utilisant les méthodes présentées est appliqué à la validation des données d'un procédé pétrochimique
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Ferreira, Alexandre da Silva. "Aplicação do algoritmo SEBAL para estimativa da evapotranspiração na mesorregião do sul goiano." Universidade do Estado do Rio de Janeiro, 2011. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=4155.
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As preocupações com o uso da terra têm permeado inúmeros estudos científicos, no âmbito nacional e internacional, voltados para a avaliação dos impactos ambientais causados pelas atividades agropecuárias. Alguns processos do ciclo hidrológico, a exemplo da evapotranspiração apresentam modificações consideráveis, devido às constantes mudanças nos usos dos solos. Desta forma, o presente trabalho busca destacar o problema das rápidas e intensas mudanças no uso do solo oriundas da expansão da atividade agropecuária e seus impactos ao meio ambiente, especialmente sobre o processo da evapotranspiração regional, na mesorregião do Sul Goiano, região típica de cerrado, localizada no centro-oeste brasileiro. A aplicação do algoritmo Surface Energy Balance Algorithm for Land - SEBAL consistiu o cerne da metodologia utilizada, com vista à estimativa dos fluxos de energia e da evapotranspiração em escala regional, obtidos com base no equacionamento do balanço de energia à superfície, complementado por dados de temperatura do ar e velocidade do vento adquiridos em estações meteorológicas (PCDs) instaladas na área de estudo. Foram utilizados dados do sensor MODIS/TERRA dos anos 2006, 2007, 2008, 2009 e 2010. O algoritmo foi testado em sua forma clássica e modificado por alterações nos critérios de seleção dos pixels âncoras, utilizados no procedimento da estimativa do fluxo de calor sensível. Pode-se concluir que a alteração dos critérios influenciou positivamente os resultados obtidos e que os valores da evapotranspiração, na região estudada, indicaram a potencialidade da metodologia empregada para o monitoramento sistemático dos componentes do balanço de energia em escala regional.<br>Concerns over land use have permeated many scientific studies at the national and international, aimed at assessing the environmental impacts caused by agricultural activities. Some processes of the hydrological cycle, such as the present evapotranspiration significant changes, due to constant changes in land uses. Thus, this paper seeks to highlight the problem of rapid and intense changes in land use arising from the expansion of agricultural activities and their impacts on the environment, especially on the process of regional evapotranspiration in southern Goiás Greater Region, a region typical of cerrado located in central Brazil. The application of the algorithm "Surface Energy Balance Algorithm for Land - SEBAL" was the core of the methodology used for the estimation of energy fluxes and evapotranspiration on a regional scale, based on the obtained solution of the surface energy balance, supplemented by data of air temperature and wind speed acquired in weather stations (PCDs) installed in the study area. We used data from MODIS / TERRA the years 2006, 2007, 2008, 2009 and 2010. The algorithm was tested in its classic form and modified by changes in the criteria for selecting pixels anchors used in the procedure of estimating the sensible heat flux. It can be concluded that the change in criteria positively influenced the results obtained and the values of evapotranspiration in the study area, indicated the potential of the methodology used for the systematic monitoring of the components of energy balance on a regional scale.
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Pelletier, François. "Mise au point d'observateurs d'état pour le suivi de cultures de cellules animales." Vandoeuvre-les-Nancy, INPL, 1995. http://www.theses.fr/1995INPL135N.
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L’objectif de ce travail est l'élaboration d'outils d'estimation d'état simples d'emploi pour l'évaluation de la composition des milieux de culture cellulaires. La première partie concerne le développement d'un nouvel estimateur appelé observateur à base de bilans de matière construit sur le principe de l'observateur asymptotique. Il peut être appliqué à n'importe quel type de culture. Il ne nécessite aucun réglage. La possibilité de prendre en compte certaines lois cinétiques connues permet de le faire fonctionner avec un nombre restreint de mesures. La seconde partie traite de la mise au point d'une nouvelle variante du filtre de Kalman, le filtre de Kalman auto-ajustable. Le réglage du filtre de Kalman est délicat et peut conduire à des problèmes de stabilité de l'erreur d'estimation et de convergence des valeurs estimées vers les valeurs réelles. Le filtre de Kalman auto-ajustable assura la stabilité des erreurs d'estimations avec un nombre réduit de réglages. Les deux nouveaux observateurs ont été appliqués à trois cultures d'hybridomes productrices d'anticorps monoclonaux. À partir de deux mesures expérimentales (glucose et lactate déshydrogénase ou ammoniaque et lactate déshydrogénase), la composition du milieu de culture est évaluée par les deux techniques. L’observateur à base de bilans de matière a donné de bons résultats et ceux obtenus avec le filtre de Kalman auto-ajustable sont acceptables tant que l'on ne sort pas du domaine de validité du modèle
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Silvertooth, Jeffrey C. "Estimating the Vegetative/Reproductive Balance in Cotton Growth." College of Agriculture, University of Arizona (Tucson, AZ), 2015. http://hdl.handle.net/10150/558538.
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Mostafa, S. M. "Estimation of variance components in balanced random and mixed linear models." Thesis, University of Strathclyde, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382394.
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ASSIS, Claudemir C. "Software para estimativa da eficiência energética na produção de suínos." Universidade José do Rosário Vellano, 2017. http://tede2.unifenas.br:8080/jspui/handle/jspui/190.
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Previous issue date: 2017-11-30<br>Brazilian pig farming is an important farming activity, because besides it offering food of high nutritional value to the human population, it contributes for generation of employ and income in the country. Due to the need of produce food with environmental responsibility, the swine producers have adopted waste treatment practices on their property. Each time more, it is necessary that the producer know the degree of efficiency and sustainability of the production system utilized. In this sense, the energy balance has been used as a tool indicative of the rational use of resources. However, many producers still do not estimate the energy flow because they encounter difficulties in the energy conversions and other required calculations. Therefore, the present work presents the software ENERGYSWINE developed to help technicians and producers to determine the energy efficiency in swine production systems. The ENERGYSWINE program was developed in Microsoft's integrated development environment (IDE) for software development (Visual Studio) using the C# (C Sharp), HTML5, CSS3 and JavaScript languages. For the storage of the information of the system such as user, farm, data analysis and energy balance calculation, the SQLServer database was used. From a literature review, the specific energy coefficients for each input and output component were established. The energy balance calculation by ENERGYSWINE considers the ratio between all energy produced in the system and all energy consumed. When accessing the initial screen of the program, the user must fill out the form containing 22 questions. After all fields were answered, the software calculates the energy balance of the farm, and the user can view and print the report with the summary of energy balances already done. ENERGYSWINE software has demonstrated to be a suitable tool to calculate of manner quick and easy the energy balance of swine production systems. As future perspectives, new works can be developed to incorporate new modules and reports into updated versions of the program.<br>A suinocultura brasileira é uma atividade agropecuária importante, pois, além de ofertar alimentos de alto valor nutricional para a população humana, contribui para a geração de empregos e renda no país. Indo ao encontro da necessidade de se produzir alimentos com responsabilidade ambiental os produtores de suínos têm adotado práticas de tratamento de resíduos em suas propriedades. Cada vez mais, é necessário que o produtor conheça o grau de eficiência e sustentabilidade do sistema de produção utilizado. Neste sentido, o balanço energético tem sido utilizado como uma ferramenta indicativa da racionalidade no uso de recursos. Porém, muitos produtores ainda não estimam o fluxo energético por encontrarem dificuldades nas conversões de energia e nos demais cálculos necessários. Portanto, o presente trabalho apresenta o software ENERGYSWINE desenvolvido para auxiliar técnicos e produtores a determinarem a eficiência energética em sistemas de produção de suínos. O programa ENERGYSWINE foi desenvolvido em ambiente de desenvolvimento integrado (IDE) da Microsoft para desenvolvimento de software (Visual Studio) utilizando as linguagens C# (C Sharp), HTML5, CSS3 e JavaScript. Para o armazenamento das informações do sistema tais como usuário, granja, análise dos dados e resultado do cálculo do balanço energético, utilizou-se o banco de dados SQLServer. A partir de uma revisão da literatura, os coeficientes energéticos específicos para cada componente de entrada e saída foram estabelecidos. O balanço energético calculado pelo ENERGYSWINE considera a razão entre toda energia produzida no sistema e toda a energia consumida. Ao acessar a tela inicial do programa, o usuário deve preencher o formulário contendo 22 questões. Após o preenchimento de todos os campos de respostas, o software realiza o cálculo do balanço energético da granja, podendo-se visualizar e imprimir o relatório com o resumo dos balanços energéticos já efetuados. O software ENERGYSWINE demonstrou ser uma ferramenta adequada para se calcular de maneira rápida e fácil o balanço energético de sistemas de produção de suínos. Como perspectivas futuras, novos trabalhos poderão ser desenvolvidos a fim de incorporar novos módulos e relatórios em versões atualizadas do programa.
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Silva, Bruno Bonemberger da. "Estimativa da evapotranspiração real por meio de imagens do satélite landsat 8." Universidade Estadual do Oeste do Parana, 2014. http://tede.unioeste.br:8080/tede/handle/tede/221.
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Previous issue date: 2014-12-10<br>The estimate evapotranspiration is a key factor in sustainable water management in irrigated agriculture, the actual crop water requirement established objectively, without generating waste of energy and water by excessive irrigation, and, on the other side, without compromising the agricultural production by its deficit. In this sense, the study aimed to estimate the daily actual evapotranspiration (-Etr) to local and regional scale, using Landsat 8 images (- OLI / TIRS), and additional data collected from a weather station, applying the Surface Energy Balance Algorithm for Land algorithm (- SEBAL). The study area is located in the west of Paraná, in Salto do Lontra County, consisting of irrigated agricultural area, native vegetation and urban area. It was used orbit image / site 223/78 in Julian days 336 2013 and 19, 35, 131 and 195 in 2014. The daily ETr was estimated from the latent heat flux density (LE), obtained from the equation residue of the energy balance. The algorithm consists of several steps which include radiometric calibration, the reflectance calculation, the surface albedo, vegetation index (NDVI, SAVI, and leaf area index - LAI), and emissivity, which are obtained from data from the sensor reflective bands orbital, with the surface temperature estimated from the thermal band. The results showed that the algorithm estimated the components of the energy balance, with higher values than the results generally obtained from previous studies. Concerning to the estimated Etr, there was good agreement between estimates obtained by SEBAL and by the Penman Monteith FAO 56 model, validating the algorithm. The errors between the models were less than or equal to 1.00 mm day-1, results similar to those found in the literature.<br>A estimativa da evapotranspiração é fator chave no manejo hídrico sustentável em agricultura irrigada, a real necessidade hídrica da cultura de forma objetiva, sem gerar desperdício de energia e água pelo excesso de irrigação e sem comprometer a produção pelo déficit da mesma. Neste sentido, o estudo teve por objetivo estimar a evapotranspiração real diária-ETr, para escala local e regional, utilizando imagens Landsat 8 - OLI/TIRS e dados complementares coletados de uma estação meteorológica, aplicando-se o algoritmo Surface Energy Balance Algorithm for Land - SEBAL . A área do estudo fica localizada no oeste paranaense no município de Salto do Lontra, composta por áreas agrícolas irrigadas e de sequeiro, vegetação nativa e parte urbana. Foi utilizada imagem da órbita/ponto 223/78, nos dias juliano 336 de 2013 e 19, 35, 131 e 195 de 2014. A ETr diária foi estimada a partir da densidade de fluxo de calor latente (LE), obtida do resíduo da equação do balanço de energia. O algoritmo é constituído de várias etapas que incluem calibração radiométrica, cálculo da reflectância, albedo da superfície, índices de vegetação (NDVI, SAVI e índice de área foliar - IAF) e emissividade, sendo estes obtidos a partir de dados das bandas reflectivas do sensor orbital, com a temperatura da superfície estimada a partir da banda termal. Os resultados mostraram que o algoritmo estimou os componentes do balanço de energia, com valores geralmente superiores aos resultados de outros estudos. Quanto à Etr estimada, houve boa concordância entre estimativas obtidas pelo SEBAL e o modelo Penman Monteith FAO 56, validando o algoritmo. Os erros entre os modelos foram iguais ou menores a 1,00 mm dia-1, resultados semelhantes ao encontrado em literatura.
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Calve, Leandro. "Estimativa de perda potencial de soja no Paraná através de métodos agrometeorológicos para fins de seguro agrícola." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256873.
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Orientador: Maria Angela Fagnani<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola<br>Made available in DSpace on 2018-08-18T02:13:32Z (GMT). No. of bitstreams: 1
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Previous issue date: 2011<br>Resumo: Uma das formas utilizadas em todo o mundo para minimizar os impactos financeiros ao produtor causados por eventos climáticos é o seguro rural. No Brasil, existe a necessidade de um maior investimento na análise dos riscos climáticos para a precificação do seguro agrícola, para que seja mais amplo e de melhor acesso por parte dos produtores. O objetivo deste trabalho foi verificar se, na análise do uso do balanço hídrico e da ocorrência dos veranicos, há correlação entre perdas históricas e os sinistros ocorridos em uma região e, também, com a estimativa de perda na safra corrente, permitindo com isso uma melhor análise dos riscos climáticos para o mercado segurador e para os produtores terem uma melhor ferramenta de gestão dos seus riscos. Esse trabalho foi elaborado com base nos dados históricos de seguro da cultura soja fornecidos pela Cia. de Seguros Aliança do Brasil, dados de produção do IBGE, situação de plantio e colheita da SEAB - PR e dados meteorológicos fornecidos pelo Agritempo - EMBRAPA/UNICAMP. Os municípios utilizados foram escolhidos pela representatividade na produção da soja no Estado do Paraná e diversidade climática entre eles. Foram correlacionados os dados de veranicos com os sinistros ocorridos, bem como calculados os Balanços Hídricos decendiais e diários da cultura e também correlacionados com as sinistralidades ocorridas. Verificou-se que, para a análise de risco do seguro da cultura da soja, as probabilidades de ocorrências de veranicos entre 6 e 11 dias são os que têm melhor correlação com os sinistros. Além disso, com a análise de perda potencial obtida através do Balanço Hídrico Diário da cultura, pode-se observar os períodos responsáveis pelas quedas de produção que influenciam os avisos de sinistros em cada município. A análise das probabilidades de ocorrência de veranicos junto com a análise da perda potencial da produção da cultura da soja, nos municípios estudados, mostrou-se como boa ferramenta para a análise do risco de ocorrências de sinistros por seca. Isto permitiu a elaboração de uma metodologia para análise de risco climático tanto para os produtores planejarem melhor o plantio, através da escolha de variedades e datas mais adequadas de plantio, quanto para as empresas seguradoras terem sustentação para poderem calcular mais eficientemente seus riscos e suas taxas<br>Abstract: Crop Insurance is one of the ways used around the world to minimize financial impacts to farmers caused by extreme weather events. In Brazil, it is necessary a greater investment in climate risk management to development rates, to expand and improve access to insurance market by producers. The aim of this study was to verify by analysis, the use of water balance associated with the probability of dry periods has a correlation between historical losses and claims incurred and also with the estimated loss in the current season, thus allowing a better analysis of climate risks to the insurance market for producers and provide a robust tool for managing their risk of loss of production. This work was based on historical data base of soybean crop insurance provided from Companhia de Seguros Aliança do Brasil, crop yield data from IBGE, context of planting and harvesting of SEAB - PR and meteorological data provided by Agritempo - EMBRAPA/UNICAMP. The cities studied were chosen for representation in soybean production in Paraná and climatic diversity among them. Data were correlated with dry spells for claims incurred and calculated daily water balance method decennial and culture and also correlated with the claim occurred. It was found that for the analysis of insurance risk of soybean, the probabilities of occurrence of dry spells between 6 and 11 days are those with the best correlation with the claims. Furthermore, the analysis of loss potential obtained from daily water balance of the crops can be observed responsible periods for yield decrease that have influenced the notices of claims in each county. Analysis of the likelihood of droughts along with analysis of the potential loss of soybean production in the counties studied, proved to be a good tool for analyzing the risk of claim by drought. This allowed the elaboration of climate risk methodology analysis to producers plan better by choosing the planting of more suitable varieties and dates of planting more appropriate, and to support the insurance companies have to be able to more efficiently calculate their risks and charges<br>Mestrado<br>Planejamento e Desenvolvimento Rural Sustentável<br>Mestre em Engenharia Agrícola
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Oliveira, Zanandra Boff de. "Estimativa da evapotranspiração a partir de dados diários de previsão meteorológica." Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/3631.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico<br>The real time determination and future of evapotranspiration (ET) can contribute to
more efficient management of irrigation. The objective of this study was: (i) to evaluate
the accuracy of the estimate of the reference evapotranspiration (ETo) calculated on
daily data of the weather forecast for seven future days (EToest), to different locations,
growing seasons and periods with and without and rain; (Ii) evaluate the impact of
using the EToest in the water balance of a soil cultivated with corn. The estimate ETo
was performed to Santa Maria - RS and Crystalline and Morrinhos - GO. The collection
of weather forecast data was carried out between June 26, 2011 to March 31 2014
was collected-daily (6:00 AM), the site: http://www.tempoagora.com.br/, the forecast
data maximum temperature (Tmax) and minimum (Tmin) air, maximum relative humidity
(RHmax) and minimum (RHmin) and wind speed (U2) for the next seven days. The EToest
calculation was carried out by FAO-Penman-Monteith (FAO PM) and Hargreaves
methods. The ETo observed day (EToday) was calculated by the FAO- PM method with
data measured by automatic weather station of the National Institute of Meteorology
(INMET). The values of EToest (est+1 the est+7) were compared with the values
observed daily (ETodia). The accuracy of the estimated EToest was evaluated using
statistical indicators (coefficient of determination - R2, slope - b, mean square error of
the square root -RMSE and average error - ME). For the analysis of the water balance
of a soil cultivated with corn, a field experiment was accomplished in the year 2011/12,
in an area of UFSM. The experimental design was a completely randomized factorial
design with four replications. The factor "A" consisted of two methods of calculation to
estimate crop evapotranspiration (ETc): (i) using crop coefficient (Kc) and simple; (Ii)
using dual Kc. The "D" factor consisted of four irrigation strategies: (i) 100%
replacement of ETc; (ii) 75% replacement of ETc; (iii) 50% of ETc and replacement;
(iv) 25% of replacement etc. The volumetric water content and available soil were
simulated is compared with the measured (100% tartamento simple Kc). The results
are an overestimation of EToest (>0,04 and <0,72 mm day-1) for the three sites,
attributed to overestimation of Tmax by the weather forecast, a variable that showed
high association with EToest (R2 0,60). This overestimation of EToest is reduced as the
estimation approximates the observed daily. The differences between the ETodia and
EToest, has small inlfuência the results of the soil water balance (RMSE less than 10
mm for the available water). Thus, EToest can be an alternative for determining the
need for crop irrigation in future time, contributing to the management of irrigated
activity and for the most efficient use of natural resources and other agricultural.<br>A determinação em tempo real e futuro da evapotranspiração (ET) pode contribuir
para a maior eficiência no gerenciamento da irrigação. Assim, o objetivo do presente
trabalho foi: (i) avaliar a precisão da estimativa da evapotranspiração de referência
(ETo) calculada com dados diários da previsão meteorológica para sete dias futuros
(EToest), para diferentes locais, anos agrícolas e períodos com e sem chuvas e; (ii)
avaliar o impacto da utilização da EToest no balanço hídrico de um solo cultivado com
milho. A estimativa da ETo foi realizada para Santa Maria - RS e para Cristalina e
Morrinhos - GO. A coleta de dados da previsão meteorológica foi realizada entre 26
de junho de 2011 a 31 de março de 2014. Coletou-se, diariamente (6:00 AM), do site:
http://www.tempoagora.com.br/, os dados de previsão de temperatura máxima (Tmax)
e mínima (Tmin) do ar, umidade relativa máxima (RHmax) e mínima (RHmin) do ar e
velocidade do vento (U2), para os próximos sete dias. O cálculo da EToest foi realizado
pelos métodos FAO-Penman-Monteith (FAO PM) e Hargreaves. A ETo do dia
observado (ETodia) foi calculada pelo método FAO PM, com dados medidos pela
estação meteorológica automática do Instituto Nacional de Meteorologia (INMET). Os
valores de EToest (est+1 a est+7) foram comparados com os valores do dia observado
(ETodia). A precisão da estimativa da EToest foi avaliada a partir de indicadores
estatísticos (coeficiente de determinação - R2, coeficiente angular - b, raiz quadrada
do erro quadrático médio -RMSE e erro médio - ME). Para a análise do balanço hídrico
de um solo cultivado com milho, um experimento de campo foi realizado no ano
agrícola 2011/12, em área experimental da UFSM. O delineamento experimental
utilizado foi o inteiramente casualizado, bifatorial, com quatro repetições. O fator A
constituiu de duas metodologias de cálculo para a estimativa da evapotranspiração da
cultura (ETc): (i) utilizando coeficiente de cultivo (Kc) simples e; (ii) utilizando Kc dual.
O fator D foi constituído de quatro estratégias de irrigação: (i) 100% de reposição da
ETc; (ii) 75% de reposição da ETc; (iii) 50% de reposição da ETc e; (iv) 25% de
reposição da ETc. O conteúdo volumétrico e a água disponível no solo simulados
foram comparados com os medidos (tratamento 100% com Kc simples). Os resultados
são de uma superestimativa média da EToest (>0,04 e <0,72 mm dia-1) para os três
locais, atribuída a superestimativa da Tmax pela previsão meteorológica, variável que
apresentou elevada associação com a EToest (R2 de 0,60). Essa superestimativa da
EToest é reduzida à medida que a estimativa se aproxima do dia observado. As
diferenças entre a ETodia e a EToest, tem pequena inlfuência nos resultados do balanço
hídrico do solo (RMSE inferior a 10 mm para a água disponível). Assim, a EToest pode
ser uma alternativa para a determinação da necessidade de irrigação das culturas em
tempo futuro, contribuindo para o gerenciamento da atividade irrigada e para a maior
eficiência na utilização dos recursos naturais e demais insumos agrícolas.
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Romano, Arthur Miguel. "Estimativa da economia de água potável nos campi." Universidade Federal de Uberlândia, 2017. https://repositorio.ufu.br/handle/123456789/18657.
Full textAbstract:
Este trabalho busca estimar a eficiência da economia de água potável no Campus Santa Mônica, Universidade Federal de Uberlândia, utilizando reservatórios de água pluvial para a substituição de água tratada por água de chuva para fins não potáveis. Por meio de informações obtidas junto a Prefeitura Universitária foi possível estimar a demanda diária de água de abastecimento para os Blocos desse Campus, em especial para aqueles com predominância de salas de aulas. A fim de verificar a capacidade de obtenção de água de chuva nas áreas impermeáveis buscou-se no site Hidroweb da Agência Nacional de Águas (ANA) os dados de precipitação diários no período de 1980 a 2015. Com as informações de oferta e demanda de água das principais edificações da área de estudo, construiu-se em Planilhas Eletrônicas, o balanço hídrico diário e a estimativa da eficiência de reservatórios na faixa de volume de 10 a 80m . O período médio de retorno do capital investido variou de 4,1 a 41,3 anos em função das características de cada bloco, tais como: área do telhado, volume do reservatório e demanda. Verificou-se que a escolha do reservatório com base apenas na porcentagem da demanda atendida é ineficaz, o bloco 3Q, por exemplo, apresentou para a demanda 10L/discente.dia uma porcentagem de demanda atendida 32% e 65% superior respectivamente as demandas de 15 e 20L/discente.dia, porém a economia média anual de água potável para a demanda de 20L/discente.dia foi, em média, 9% e 24% maior que as economias médias das demandas de 15 e 10L/discente.dia respectivamente. Além disso, através de uma regressão linear múltipla foram propostas fórmulas para o cálculo da economia anual nos campi da UFU em função do tipo de telhado da cobertura, da população do bloco, do volume do reservatório de armazenamento instalado, da demanda diária por água e da área total da cobertura. Para todos os campi da UFU o coeficiente de correlação R foi superior a 0,83.<br>This work seeks to estimate the efficiency of the drinking water economy in the Santa Mônica Campus, Federal University of Uberlândia, using rainwater reservoirs to replace rainwater treated water for non potable purposes. By means of information obtained from the University City Hall, it was possible to estimate the daily supply water demand for the Blocks of this Campus Especially those with a predominance of classrooms . In order to verify the capacity to obtain rainwater in the impermeable areas, the daily rainfall data from 1980 to 2015 was searched on the National Water Agency's website (Hidroweb). With the information on water supply and demand Of the main buildings in the study area, it was built on Electronic Sheets, the daily water balance and the estimation of the efficiency of reservoirs in the volume range of 10 to 80m3. The average return period of invested capital ranged from 4.1 to 22.8 years, depending on the characteristics of each block, such as roof area, reservoir volume and demand. It was verified that the choice of the reservoir based only on the percentage of the demand served is ineffective, for example, block 3Q presented a demand percentage of 32% and 65%, respectively, higher than demand Of 15 and 20L / student.day, but the average annual saving of drinking water for the demand of 20L / student.day was on average 9% and 24% higher than the average savings of 15 and 10L / student demands. Day respectively. In addition, through a multiple linear regression, formulas were proposed for the calculation of the annual savings in UFU campuses according to the type of coverage roof, the population of the block, the volume of installed storage tank, daily demand for water and Of the total coverage area. For all UFU campuses the correlation coefficient R was higher than 0.83.<br>Dissertação (Mestrado)
42
Balland, Laurent. "Contribution à l'estimation des paramètres cinétiques et énergétiques de systèmes chimiques en milieux homogène et hétérogène dans un réacteur calorimétrique." Rouen, 1997. http://www.theses.fr/1997ROUES054.
Full textAbstract:
Le présent travail propose une méthodologie pour estimer les paramètres cinétiques et thermiques de modèles de comportement énergétique de milieux réactionnels chimiques dans des conditions de synthèse aussi proches que possible des conditions industrielles. Des réactions chimiques, accompagnées de phénomènes physiques tels que la solubilisation ou le mélangeage de réactifs, sont réalisées dans un réacteur calorimétrique (RC1 de Mettler (R)) qui détermine la puissance expérimentale dégagée par le milieu. La méthode consiste à ajuster les paramètres du modèle reproduisant ce même dégagement de puissance. Un modèle incluant le transfert de matière couplé a la réaction chimique prend en compte la miscibilité progressive du réactif introduit. Dans le cas des réactions sans solvant, la variation du comportement du milieu réactionnel, au fur et à mesure de l'avancement de la réaction, est considérée selon trois approches. La première repose sur un modèle phénoménologique global et donne des résultats satisfaisants mais d'application limitée. Une deuxième approche, consistant à remplacer les concentrations par les activités dans les équations cinétiques, n'a pas abouti à des résultats concluants. La troisième approche prend en compte de manière beaucoup plus précise : l'aspect énergétique, en déterminant les enthalpies molaires d'excès du mélange forme par les réactifs et les produits ; l'aspect cinétique, en approfondissant le mécanisme chimique. Cette dernière approche fournit des résultats plus précis et extrapolables. Des méthodes spécifiques d'estimation ont été mises au point en couplant des méthodes globalement convergentes et localement convergentes : un maillage simple de l'espace des paramètres et un algorithme génétique fournissent des points d'initialisation pour une méthode de Rosenbrock. Les modèles sont transcrits au sein d'un logiciel développé en langage C++ sous environnement Windows (TM).
43
Moreira, LuÃs ClÃnio JÃrio. "Estimating irrigated watermelon evapotranspiration using sebal, soil-water balance and eddy correlations." Universidade Federal do CearÃ, 2009. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=5217.
Full textAbstract:
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico<br>In applications of the SEBAL (Surface Energy Balance Algorithm for Land) algorithm parameters for physical processes adjusted for other regions of the planet are commonly used. Therefore, there is a need for validation of the estimates made with the algorithm compared with other conventional methods of estimating evapotranspiration. Thus, this study main goal was to evaluate the satellite-based algorithm to estimate evapotranspiration of irrigated watermelon using as comparative methods: soil water balance and eddy correlation. The studied area was a plot of 1 ha located in the irrigated district of the low Acaraà River. Foliar coverage was obtained from digital images taken from a camera. Sensors were installed from the soil surface to a height of 1.5 m for monitoring the temperature in the air. The unsaturated hydraulic conductivity function of the soil was obtained using the instantaneous profile method. The water balance in the soil was done on days 17, 18 and 19 December, 2008, in the 0 to 30 cm depth using soil moisture capacitive sensors. To evaluate the components of net radiation and evapotranspiration using the method of eddy correlation, a micrometeorological tower was installed in the center of the studied area, where latent heat flux (LE), sensible heat flux (H) and evapotranspiration were determined. With climate data from a meteorological station nearby and using the FAOÂs methodology, net radiation (Rn) and soil heat flow (G) were determined. The SEBAL algorithm was applied in two Landsat5 satellite images acquired in 17/12/2008 and 02/01/2009 for estimating the net radiation and daily evapotranspiration. The measured temperature at the soil surface and in the air at 10 cm high was over 40  C near noon time. The unsaturated hydraulic conductivity function found was of the form K (θ) = 0.089 e28, 53θ and K (θ) = 0.0469 e48, 773θ, respectively for 0 - 15 and 15 - 30 cm. The evapotranspiration obtained from soil water balance with capacitive sensors in the study period was 9.37; 12.18 and 11.27 mm day-1, respectively in 17; 18 and December 19, 2008. For the radiation balance it was found that the latent heat flux was underestimated by using the method of eddy correlation with maximum values of the order of 150 W m-2. The sensible heat flux was always larger than the LE during the day, with maximum values near 300 W m-2. The energy balance done but accounting H + LE and Rn â G produced a residual error of around 60%. The daily average values of ETc (eddy correlations) for part of the experimental period were in the range of 0.91 to 1.18 mm day-1, with an average of 0.96 mm day-1. The satellite image that was applied to SEBAL algorithm presented many clouds, affecting the estimation of the components of radiation balance and evapotranspiration. In the area of watermelon, SEBAL estimates of evapotranspiration for dates 17/12/2008 and 02/01/2009 were 6.5 and 4.0 mm day-1, respectively. For validation, the ETo obtained by Penman-Montheith method at the time of satellite overpass was 0.53 mm h-1, while Etc obtained with SEBAL, eddy correlation and soil-water balance was 0.78; 0.11 and 0.55 mm h-1, respectively.<br>Nas aplicaÃÃes feitas com o SEBAL (Surface Energy Balance Algorithm for Land), estÃo sendo utilizadas parametrizaÃÃes de processos fÃsicos ajustados para outras regiÃes do planeta. Portanto, existe uma necessidade de validaÃÃo das estimativas feitas com o algoritmo comparando com outros mÃtodos usuais de estimativa de evapotranspiraÃÃo. Assim, esse trabalho teve como objetivo avaliar o algoritmo SEBAL na estimativa da evapotranspiraÃÃo da melancia irrigada usando como mÃtodos comparativos o balanÃo hÃdrico no solo e mÃtodo das correlaÃÃes turbulentas (eddy correlation). A Ãrea estudada foi um lote de 1 ha localizado no PerÃmetro Irrigado Baixo AcaraÃ. A cobertura Foliar foi obtida a partir de fotografias digitais. Foram instalados sensores a partir da superfÃcie do solo atà a altura de 1,5 m para monitoramento da temperatura no ar. Para fazer o balanÃo hÃdrico no solo foi encontrada a funÃÃo da condutividade hidrÃulica nÃo saturada atravÃs da metodologia do perfil instantÃneo. O balanÃo hÃdrico no solo foi feito nos dias 17, 18 e 19/12/2008 na camada de 0 a 30 cm usando sensores capacitivos de umidade. Para avaliar os componentes do balanÃo de radiaÃÃo e a evapotranspiraÃÃo atravÃs do mÃtodo das correlaÃÃes turbulentas foi instalada uma torre micrometeorolÃgica no centro da Ãrea, onde o fluxo de calor latente (LE), o fluxo de calor sensÃvel (H) e a evapotranspiraÃÃo foram determinados. Com dados climÃticos de uma estaÃÃo meteorologia prÃximo a Ãrea e usando a metodologia da FAO foi estimado a radiaÃÃo lÃquida (Rn) e o fluxo de calor no solo (G). O algoritmo SEBAL foi usado nas imagens do TM-Landsat 5 dos dias 17/12/2008 e 02/01/2009 para estimar o balanÃo de radiaÃÃo e a evapotranspiraÃÃo diÃria. A temperatura na superfÃcie e a 10 cm de altura prÃximos ao meio dia foi superior a 40ÂC. A funÃÃo da condutividade hidrÃulica no solo nÃo saturado para camada de 0 â 15 e 15 â 30 cm foi: K(θ) = 0,089e28,53θ e K(θ) = 0,0469e48,773θ, respectivamente. A evapotranspiraÃÃo obtida atravÃs do balanÃo hÃdrico com sensores capacitivos nos dias analisados foi 9,37; 12,18 e 11,27 mm dia-1, respectivamente em 17; 18 e 19 de dezembro de 2008. No balanÃo de energia observou-se que o fluxo de calor latente foi subestimado usando o mÃtodo das correlaÃÃes turbulentas apresentando valores mÃximos no dia nunca superiores a 150 W m-2. O fluxo de calor sensÃvel esteve sempre maior que o LE durante o dia, apresentando valores mÃximos prÃximos a 300 W m-2. O erro de fechamento da equaÃÃo do balanÃo de energia obtido atravÃs do equacionamento entre H + LE e Rn â G foi de cerca de 60%. Os valores mÃdios diÃrios da ETc (correlaÃÃes turbulentas) para parte do perÃodo experimental estiveram na faixa de 0,91 a 1,18 mm dia-1, com mÃdia de 0,96 mm dia-1. As imagens de satÃlites em que foi usado o algoritmo SEBAL apresentaram nuvens comprometendo a estimativa dos componentes do balanÃo de radiaÃÃo e a evapotranspiraÃÃo. Na Ãrea da melancia, a evapotranspiraÃÃo diÃria usando o SEBAL nos dias 17/12/2008 e 02/01/2009 foi 6,5 e 4,0 mm dia-1, respectivamente. Na anÃlise comparativa, a ETo na hora da passagem do satÃlite foi de 0,53 mm h-1, enquanto a ETc foi de 0,78; 0,11 e 0,55 mm h-1 estimada com o SEBAL, mÃtodos das correlaÃÃes turbulentas e balanÃo hÃdrico, espectivamente.
44
Meister, R. "Estimating Antarctic ice sheet mass balance from gravimetry and altimetry." Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1364858/.
Full textAbstract:
Estimates of the Antarctic ice sheet mass balance from the past ten years show great discrepancy. Deriving mass values from gravity measurements is a ffected by corrections for postglacial rebound (PGR). Calculating Antarctic ice sheet mass balance from altimetry satellites requires knowledge of surface densities. Here, two instruments were used in conjunction to constrain ice sheet mass balance. Surface height trends from the Envisat radar altimeter and mass trends from GRACE were analysed for the period January 2003 until October 2010. An analysis of errors related to GRACE gravity measurements was carried out and a best method for removal of errors was chosen. Envisat altimetry corrections were examined. Envisat surface height trends were converted into units of mass and smoothed with a 300km Gaussian filter in order to be compatible with the GRACE mass trend. This was done using a) the density of ice (917kg=m3), b) a firn density of 450kg=m3 and c) a variable surface density map of the Antarctic derived from observations of changes in the pattern of surface height trends. Subtracting the altimetry mass trend from the GRACE mass trend provides results dominated by the absence of altimetry data in the Antarctic peninsula and south of 81:6 degrees south. Therefore, ICESat altimetry trend values were added to the Envisat trend map, where available. The GRACE mass trend and the smoothed altimetry trend converted to mass show very good agreement. The diff erence between GRACE and the combined Envisat-ICESat altimetry trends can be interpreted as a combination of PGR and error. Integrating this di fference provides considerably smaller PGR values than all commonly used PGR models. The integrated area trends from both gravimetry and altimetry show mass loss for West Antarctica, mass gain for East Antarctica and an acceleration of melting in the Amundsen Sea Sector.
45
Degbey, Octavien. "Optimisation statique hiérarchisée des systèmes de grandes dimensions : Application à l'équilibrage de bilans de mesures." Nancy 1, 1987. http://www.theses.fr/1987NAN10158.
Full textAbstract:
Optimisation statique hiérarchisée des systèmes industriels ; traitement hiérarchisé de l'équilibrage des bilans de mesure pour des systèmes statiques décrits par des équations de modèles multilinéaires homogènes à paramètres inconnus
46
Karam, Hanan Nadim. "Estimating evapotranspiration from the Amazon Basin using the atmospheric water balance." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/35086.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2006.<br>Includes bibliographical references (p. 98-101).<br>The spatio-temporal patterns of evapotranspiration (ET) in the Amazon basin are still poorly understood. Field studies in the Amazonian forest have shown that at some sites, deep roots allow trees to sustain elevated transpiration during several months of minimal rainfall, whereas at others, trees experience evident dry season water limitation. However, the few sites investigated are inadequate to characterize the conditions of transpiration throughout the basin. As a result of this uncertainty in modeling trees' access to deep soil moisture, land surface models cannot provide reliable estimates of transpiration in the region. From a basin-averaged perspective, it remains uncertain whether transpiration is water-limited, peaking during the basin's wet season, or energy-limited, peaking during the dry season when clearer skies allow for higher surface radiation. In this work, we investigate an approach to deriving a spatially-averaged ET estimate for the Amazon basin, which avoids modeling the forest's terrestrial hydrology. ET is computed as a residual of the atmospheric water balance, using basin-averaged convergence of atmospheric water vapor flux [C], precipitation [P], and tendency of total atmospheric water vapor [dw/dt] as inputs.<br>(cont.) As our resulting estimate of ET is only as good as the input estimates of the other hydrologic components, we analyze multiple cutting-edge datasets that may be used to compute these components. [P] data are obtained from GPCP and TRMM products. The three global reanalyses, NCEP/NCAR, NCEP/DOE and ECMWF ERA-40 provide data on atmospheric fields to compute [C] and [dw/dt]. The large discrepancies between [C] estimates produced by the different reanalyses, interpreted as uncertainty in these estimates, led to a thorough investigation of data on this field over a time period dating back to 1980. Concurrent time series of precipitation and Amazon river discharge are used to evaluate the accuracy of the various reanalyses in simulating [C] at the monthly and annual timescales. A measure of the random error associated with [C] estimates from each data source is derived, and used as a weighting factor to combine information from the three reanalyses. The resulting estimates of monthly basin-averaged ET are significantly lower in their long-term mean than estimates published in the literature. The resulting climatological annual cycle of basin-averaged ET suggests a switch between water and energy limited conditions for transpiration over a year's duration.<br>by Hanan Nadim Karam.<br>S.M.
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Fischer, Sandra. "Exploring a Water Balance Method on Recharge Estimations in the Kilombero Valley, Tanzania." Thesis, Stockholms universitet, Institutionen för naturgeografi och kvartärgeologi (INK), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-92345.
Full textAbstract:
Simple models that require little input data and are easy to use is the ideal case within hydrology. Basic water balance principles often represent such approaches as the method on rainfall-runoff relationship developed by Sutcliffe et al. in India in 1981. That was tested for the Kilombero Valley in Tanzania in order to estimate the recharge to the soil and sub-surface systems. Measured annual runoff in the streams was compared to the seasonal net rainfall to give the difference as potential recharge. This was done for five separate sub-catchment where the hillslope catchments gave a smaller proportion of the net rainfall to occur as surface runoff compared to the valley-catchments. Due to the difference in hydrologic setting from the original model site in India to the Kilombero Valley (e.g. a wetland and stream type), the soil moisture recharge could not be estimated. Also, corrections are needed to the data preparation process and the state of the original stream flow data is questionable. Thus, the results were interpreted as an indication on how the water resources could be moving in the system. An explaining theory that captured the difference between the landform types is mountain system recharge. That implied that all surplus rainfall generated in the mountains has a potential to eventually recharge the groundwater. The method tested, though its simple general concepts, could not alone give satisfying results for the Kilombero Valley system. However, this study convey the importance of continuous exploration of methods to describe the environment in a simplified way.
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Jacomazzi, Marco Antonio. "Programa para estimativa do rendimento das culturas pela simulação da irrigação por balanço hídrico sequencial." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/11/11143/tde-05012005-162947/.
Full textAbstract:
A utilização de recursos computacionais para o planejamento do uso racional da água em sistemas irrigados é cada vez mais freqüente na agricultura moderna tecnificada. Devido a constante melhoria desses recursos, torna-se, essencial a atualização dos programas desenvolvidos, específicos na área de irrigação e drenagem, incorporando as recentes tecnologias desenvolvidas neste setor. O objetivo deste trabalho foi elaborar uma ferramenta computacional de acesso simplificado, que proporcionasse ao usuário, a liberdade quanto aos critérios empregados nas áreas irrigadas. O programa desenvolvido é específico para o planejamento de sistemas irrigados. Esse programa foi desenvolvido para auxiliar na tomada de decisão sobre o nível de manejo de irrigação a ser adotado; com base numa previsão de chuvas simulada a partir de uma série histórica de dados e qual a máxima produtividade esperada da cultura para um determinado momento de irrigação. Como parâmetros de entrada o aplicativo requer dados sobre os parâmetros climáticos regionais; as características da cultura irrigada; as propriedades do solo quanto à capacidade de armazenamento de água e operação do manejo de água adotado. O aplicativo permite, a partir dos dados climáticos disponíveis, estimar a evapotrasnpiração potencial utilizando-se desde o modelo de Penman, que exige maior número de variáveis até o de Thornthwaite que se baseia apenas na temperatura. Simulando-se diferentes níveis de manejo da irrigação para a região de Piracicaba, onde o déficit hídrico não é acentuado, as simulações não apresentaram diferenças significativas, entretanto, supõem-se que os contrastes poderão ser potencializados para regiões mais áridas. Essa ferramenta apresentou-se ser bastante útil para o usuário, para as diferentes regiões climáticas no país e os dados climáticos disponíveis para cada caso.<br>The use of computers resources for planning the rational water use in irrigated systems is even more frequent in the modern technical agriculture. Due to the constant improvements of those resources, it is essential to update the developed softwares, specifically in the irrigation and drainage area, by incorporating the most recent technologies developed in this segment. The objective of this work was to elaborate a computation easy to handle tool, which allows freedom to act in relation to the used criteria in irrigated farming. The developed software is specific for planning of irrigated systems. It was developed to help decisions taking about the irrigation management level to be adopted; based on a rainfall forecast simulated on an historically sequence and the maximum crop yield expected for a specific irrigation moment. As input data, the software will need (i) regional climatic parameters, (ii) the characteristics of irrigated crop, (iii) soil properties related to water storage capacity and (iv) the adopted water management. Based on available data, user can choose among several methods of calculate the potential evapotranspiration, from Penman, which will need more climatic data, until Thornthwaite based on temperature data only. By running the program with data from Piracicaba region, where there is not a significant water deficit along the year, no difference was shown among the different methods used, but it is to suppose that in more arid regions the contrast among them will be more significantly. The developed tool presents to be useful for the user by being flexible regarding the different climatic regions of the country and also regarding available data set for each case.
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Francisco, João Paulo. "Estimativa da transpiração de pinhão-manso com a utilização do método de dissipação térmica." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/11/11152/tde-16082017-153135/.
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Atualmente o mundo vive uma fase de mudança da matriz energética, onde fontes mais limpas e renováveis de energia estão sendo cada vez mais utilizadas. Considerando o eminente cenário de escassez dos recursos hídricos, além da necessidade de produzir energia mais limpa, existe a necessidade de racionalizar o uso da água e para isso é preciso estudar o consumo hídrico das culturas. Assim, este projeto terá como objetivos calibrar e utilizar medidas de fluxo de seiva obtidas pelo método de dissipação térmica (MDT) para determinar a transpiração do pinhão-manso (Jatropha curcas L.). Para a calibração foram utilizadas plantas de pinhão-manso cultivadas em casa de vegetação dentro de vasos de 250 L. Estes vasos foram acondicionados sobre lisímetros de pesagem e tiveram sua superfície coberta para evitar a evaporação da água do solo. A calibração foi realizada durante 60 dias consecutivos, quando durante os primeiros 15 dias o solo foi mantido com umidade próxima da condição de capacidade de vaso por meio de irrigações frequentes, seguido de 30 dias de redução da umidade do solo devido a supressão da irrigação e de 15 dias finais com o retorno da irrigação para a recuperação da hidratação das plantas. A transpiração foi determinada nos lisímetros e estes dados foram utilizados para calibrar as medidas obtidas por sensores de fluxo de seiva inseridos no tronco das plantas. Após a calibração, os sensores foram instalados em campo para monitorar a transpiração de plantas cultivadas sob irrigação por pivô central, gotejamento e sem irrigação. Aliado a diferentes tipos de poda a que foram submetidas as plantas, avaliou-se a combinação do consumo de água das plantas de pinhão-manso associado a estes tratamentos de podas. Como esperado o método de dissipação térmica apresentou-se como sendo confiável para determinação da transpiração de pinhão-manso, permitindo que a metodologia pudesse ser utilizada em campo. Foi verificado efeito significativo da irrigação, dos tipos de poda e da época de avaliação após a poda para a altura de plantas, diâmetro e volume de copa e IAF. Observou-se valores de ETc de 6,96; 7,54 e 6,57 mm dia-1 para os tratamentos de irrigação localizada, pivô central e sem irrigação, respectivamente.<br>Today the world is going through a phase of changing the energy matrix, where cleaner and renewable sources of energy are being used more and more. Considering the imminent scenario of scarcity of water resources, in addition to the need to produce cleaner energy, there is a need to rationalize the use of water and for this we must study the water consumption of crops. Thus, this project will aim to calibrate and use sap flow measurements obtained by the thermal dissipation probe to determine Jatropha curcas L. transpiration. For the calibration, jatropha plants grown under greenhouse conditions were used in 250 L vessels. These vessels were placed on weighing lysimeters and had their surface covered to avoid evaporation of soil water. The calibration was carried out during 60 consecutive days, which during the first 15 days the soil was maintained with humidity near the pot capacity by means of frequent irrigations, followed by 30 days of soil moisture reduction due to suppression of irrigation and of 15 days with the return of irrigation to the recovery of plant hydration. The transpiration was determined in the lysimeters and these data were used to calibrate the measurements obtained by sap flow sensors inserted in the trunk of the plants. After the calibration, the sensors were installed in the field to monitor the transpiration of plants cultivated under central pivot irrigation, drip irrigation and without irrigation. Allied to the different types of pruning to which the plants were submitted, the combination of the water consumption of the jatropha plants associated to these pruning treatments was evaluated. As expected, the thermal dissipation method proved to be reliable for the determination of perspiration of Jatropha, allowing the methodology to be used in the field. It was verified a significant effect of irrigation, pruning types and evaluation period after pruning for plant height, canopy diameter and volume and LAI. ETc values of 6.96; 7.54 and 6.57 mm day-1 for the treatments of localized irrigation, central pivot and without irrigation, respectively.
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Paloschi, Rennan Andres. "Software aplicado a modelos de estimativa de produtividade agrícola." Universidade Estadual do Oeste do Parana, 2016. http://tede.unioeste.br:8080/tede/handle/tede/267.
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Previous issue date: 2016-02-04<br>Although there are studies that have been seeking modeling the influence of meteorological variables in relation to crop yield, the application of such models on a global scale and the consequent achievement concerning spatial results is a real challenge due to the complexity of the involved variables. Thus, this study aimed to analyze and implement software that allows the application of models to estimate agricultural yield based on remote sensing images, in a spatial and automated way. Yield estimation model using FAO water balance, as well as the needed indices to calculate it were implemented and subsequently tested for soybean cropping in Parana state for the 2011/2012 harvesting season. Design standards and analyses by language Unified Modeling Language (UML) were used to create a software structures and standardize computational tools. Such structures were implemented to data processing, water balance estimation and yield estimation, whose result was a version 1.0.1 software Crop-yield Modeling Platform - CyMP. Its structure makes implementation and use of estimation models more practical, automated, reusable and scalable for cropping yield. According to the proposed software, it was possible to reduce noise in vegetation indices from the orbital sensor images of Moderate Resolution Imaging Spectroradiometer - MODIS, interpolate images from the European Centre for Medium-Range Weather Forecasts ECMWF, climate model to MODIS resolution, determine FAO water balance, estimate dates of development cycle of soybean crop, estimate hydric stress factor, estimate real evapotranspiration, and finally estimate both gross potential yield and attainable yield of soybean crop in Paraná State for the 2011/2012 harvesting season.<br>Embora haja estudos que busquem modelar as influências de variáveis agrometeorológicas em relação à produtividade das culturas agrícolas, a aplicação destes modelos em escala global e a consequente obtenção de resultados de forma espacial é um verdadeiro desafio dada a complexidade de variáveis envolvidas. Assim, este trabalho buscou analisar e implementar um software que permita a aplicação de modelos de estimativa de produtividade agrícola, baseados em imagens de sensoriamento remoto, de forma espacial e automatizada. O modelo de estimativa de produtividade, utilizando o balanço hídrico FAO, assim como os índices necessários para obtê-lo, foi implementado e posteriormente testado para o cultivar soja no Estado do Paraná para a safra 2011/2012. Padrões de projeto e análises utilizando a Unified Modeling Language (UML) foram utilizados na construção de estruturas de software e padronização de ferramentas computacionais. Tais estruturas foram implementadas para tratamento de dados, estimativa de balanço hídrico e estimativa de produtividade para dar origem ao software Crop-yield Modeling Platform CyMP, versão 1.0.1. Sua estrutura torna, de formas prática, automatizada, reutilizável e escalável, a implementação e a utilização de modelos de estimativa de produtividade agrícola. De acordo com o software proposto, foi possível suavizar ruídos em índices de vegetação provenientes de imagens do sensor Moderate Resolution Imaging Spectroradiometer - MODIS, interpolar imagens provindas do modelo climático europeu - European Centre for Medium-Range Weather Forecasts ECMWF - para resolução MODIS, determinar o balanço hídrico FAO, estimar as datas do ciclo de desenvolvimento da cultura da soja, estimar o fator de estresse hídrico da cultura, estimar a evapotranspiração real e, por fim, estimar tanto a produtividade potencial bruta como a produtividade atingível da cultura da soja no Estado do Paraná para safra 2011/2012.