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216. A calibration-free evapotranspiration mapping technique for spatially-distributed regional-scale hydrologic modeling

Creator:
Szilágyi, József and Kovács, Ákos
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
spatially distributed evapotranspiration, complementary relationship of Evaporation, MODIS data, priestorové rozdelenie evapotranspirácie, komplementárny vzťah pre evapotranspiráciu, and údaje MODIS
Language:
Slovak
Description:
Monthly evapotranspiration (ET) rates over Hungary for 2000-2008 are mapped at a spatial scale of about 1 km with the help of MODIS daytime land surface temperature as well as sunshine duration, air temperature and humidity data. Mapping is achieved by a linear transformation of MODIS daytime land surface temperature values employing the complementary relationship of evaporation. Validation of the ET rates has been performed at spatial scales spanning almost three magnitudes from a few hundred meters to about a hundred kilometers employing eddy-covariance (EC) measurements and catchment water balance closures. Typically the unbiased ET estimates are within 15 % of EC values at a monthly basis, within 7 % at an annual, and within only a few percent at a multi-year basis. The ET estimates yield an especially remarkable match (relative error of 0.2 %, R2 = 0.95) with high-tower EC measurements at a monthly basis. The spatial distribution of the ET estimates confirm earlier, complex regional hydrologic model results and observations as well as yields a perfect estimate of the country’s precipitation recycling index (the ratio of the multi-year mean ET and precipitation rates spatially aggregated for the whole country) of 89.2 % vs an observed value of 89.6 %. The CREMAP method is very simple, easy to implement, requires minimal data, calibration-free, and works accurately when conditions for the complementary relationship are met. and Pomocou údajov ročlenených podľa MODIS (moderate resolution imaging spectroradiometer), s využitím dennej povrchovej teploty, trvania slnečného svitu, teploty vzduchu a jeho vlhkosti boli zostrojené mapy mesačnej evapotranspirácie (ET) Maďarska pre roky 2000-2008 s priestorovým rozlíšením približne 1 km. Mapovanie bolo zrealizované lineárnou transformáciou MODIS dennej teploty povrchu s uvážením doplňujúceho vzťahu pre evapotranspiráciu CR, navrhnutou Bouchetom (1963). Výsledky dosiahnuté touto metódou boli verifikované v priestorovej mierke pokrývajúcej tri rády od niekoľkých stoviek metrov po stovky kilometrov, použijúc merania metódou pulzácií (eddy covariance, EC), a bilanciou vody v koncovom profile povodí. Typicky, hodnoty ET sú v medziach 15 % mesačných hodnôt EC a 7 % ročných hodnôt a len v medziach niekoľkých percent viacročných hodnôt evapotranspirácie, ktoré boli určené inými metódami. Hodnoty ET sú v dobrej zhode s výsledkami meraní ET na vysokej veži metódou EC (relatívna chyba 0.2 %, R2 = 0,95). Priestorové rozdelenia vypočítaných hodnôt ET potvrdzujú predchádzajúce výsledky modelovania regionálnymi modelmi, ako aj hodnoty indexu recyklácie zrážok krajiny (precipitation recycling index), čo je pomer mnohoročnej priemernej ET a zrážok agregovaných v krajine, s hodnotou 89,2 % vs pozorovaná hodnota 89,6 %. Metóda CREMAP je jednoduchá, ľahko implementovateľná, vyžaduje minimum vstupných hodnôt, nie je ju potrebné kalibrovať a keď sú splnené podmienky jej použiteľnosti, je aj dostatočne presná.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

217. A causal-mentalist view of propositions

Creator:
Joaquin, Jeremiah Joven B. and Franklin, James
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
propositions, causal-mentalist view, cluster analysis, game theory, perception algorithms, Platonism, and symbol grounding
Language:
Slovak
Description:
In order to fulfil their essential roles as the bearers of truth and the relata of logical relations, propositions must be public and shareable. That requirement has favoured Platonist and other non-mental views of them, despite the well-known problems of Platonism in general. Views that propositions are mental entities have correspondingly fallen out of favour, as they have difficulty in explaining how propositions could have shareable, objective properties. We revive a mentalist view of propositions, inspired by Artificial Intelligence work on perceptual algorithms, which shows how perception causes persistent mental entities with shareable properties that allow them to fulfil the traditional roles of (one core kind of) propositions. The clustering algorithms implemented in perception produce outputs which are (implicit) atomic propositions in different minds. Coordination of them across minds proceeds by game-theoretic processes of communication. The account does not rely on any unexplained notions such as mental content, representation, or correspondence (although those notions are applicable in philosophical analysis of the result).
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

218. A combined CFD-experimental method for abrasive erosion testing of concrete

Creator:
Messa, Gianandrea Vittorio, Branco, Renan De Lima, Filho, José Gilberto Dalfré, and Malavasi, Stefano
Type:
article, model:article, and TEXT
Subject:
abrasive erosion, computational fluid dynamics, concrete, experiments, and two-phase flow
Language:
Slovak
Description:
Serious damage may occur to concrete hydraulic structures, such as water galleries, spillways, and stilling basins, due to the abrasive erosion caused by the presence of solid particles in the flow. This underlines the importance of being capable in providing characterization of the concrete from the point of view of its vulnerability to abrasive erosion, in order to improve the design of the structure and the material selection. Nevertheless, the existing apparatus for concrete abrasive erosion testing are either far from allowing realistic simulation of the actual environment in which this phenomenon occurs, or show a large degree of complexity and cost. An alternative method has been developed with the aid of Computational Fluid Dynamics (CFD). CFD was first employed to verify the effectiveness of a new laboratory equipment. Afterwards, a parameter has been introduced which, by successful comparison against preliminary experiments, proved suitable to quantify the effect of the fluid dynamic conditions on the concrete abrasive erosion, thereby opening the way to CFD-based customization of the apparatus. In the future, the synergy of numerical and physical modelling will allow developing predictive models for concrete erosion, making it possible to reliably simulate real structures.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

219. A comparative study of friction factor correlations for high concentrate slurry flow in smooth pipes

Creator:
Assefa, K. M. and Kaushal, D. R.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Bingham fluid, smooth pipe, laminar flow, turbulent flow, friction factor, Reynolds number, correlations, and statistical parameters
Language:
Slovak
Description:
A number of correlations for friction factor determinations in smooth pipes have been proposed in the past decades. The accuracy and applicability of these friction factor formulas should be examined. Based on this notion the paper is designed to provide a comparative study of friction factor correlations in smooth pipes for all flow regimes of Bingham fluids. Nine models were chosen. The comparisons of the selected equations with the existing experimental results, which are available in the literature, were expressed through MARE, MRE+ , MRE- , RMSE, Ѳ, and S. The statistical comparisons were also carried out using MSC and AIC. The analyses show that the Wilson-Thomas (1985) and Morrison (2013) models are best fit models to the experimental data for the Reynolds number up to 40000. Within this range, both models can be used alternately. But beyond this Re value the discrepancy of the Wilson-Thomas model is higher than the Morrison model. In view of the fact that the Morrison model requires fewer calculations and parameters as well as a single equation is used to compute the friction factor for all flow regimes, it is the authors’ advice to use this model for friction factor estimation for the flow of Bingham fluids in smooth pipes as an alternative to the Moody chart and other implicit formulae.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

220. A coupled impact of different management and soil moisture on yield of winter wheat (Triticum aestivum L.) in dry conditions at locality Mezőföld, Hungary

Creator:
Milics, Gabor
Format:
počítač and online zdroj
Type:
model:article and TEXT
Subject:
remote sensing, NDVI and moisture index, and variable rate application of phosphorus and nitrogen fertilizing
Language:
Slovak
Description:
Variable rate technology (VRT) in nutrient management has been developed in order to apply crop inputs according to the required amount of fertilizers. Meteorological conditions rarely differ within one field; however, differences in soil conditions responding to precipitation or evaporation results within field variations. These variations in soil properties such as moisture content, evapotranspiration ability, etc. requires site-specific treatments for the produced crops. There is an ongoing debate among experts on how to define management zones as well as how to define the required amount of fertilizers for phosphorus and nitrogen replenishment for winter wheat (Triticum aestivum L.) production. For management zone delineation, vegetation based or soil based data collection is applied, where various sensor technology or remote sensing is in help for the farmers. and The objective of the study reported in this paper was to investigate the effect of soil moisture data derived from Sentinel-2 satellite images moisture index and variable rate phosphorus and nitrogen fertilizer by means of variable rate application (VRA) in winter wheat in Mezőföld, Hungary. Satellite based moisture index variance at the time of sowing has been derived, calculated and later used for data comparison. Data for selected points showed strong correlation (R2 = 0.8056; n = 6) between moisture index and yield, however generally for the whole field correlation does not appear. Vegetation monitoring has been carried out by means of NDVI data calculation. On the field level, as indicated earlier neither moisture index values at sowing nor vegetation index data was sufficient to determine yield. Winter wheat production based on VRA treatment resulted significant increase in harvested crop: 5.07 t/h in 2013 compared to 8.9 t/ha in 2018. Uniformly managed (control) areas provided similar yield as VRA treated areas (8.82 and 8.9 t/ha, respectively); however, the input fertilizer was reduced by 108 kg/ha N and increased by 37 kg/ha P.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

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