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Now showing 1 - 5 of 28
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    Adaptive stochastic management of the storage function for a large, open reservoir using learned fuzzy models
    (Sciendo, 2022-06-01) Kozel, Tomáš; Starý, Miloš
    The design and evaluation of algorithms for adaptive stochastic control of the reservoir function of a water reservoir using an artificial intelligence method (learned fuzzy model) are described in this article. This procedure was tested on the Vranov reservoir (Czech Republic). Stochastic model results were compared with the results of deterministic management obtained using the method of classical optimisation (differential evolution). The models used for controlling of reservoir outflow used single quantile from flow duration curve values or combinations of quantile values from flow duration curve for determination of controlled outflow. Both methods were also tested on forecast data from real series (100% forecast). Finally, the results of the dispatcher graph, adaptive deterministic control and adaptive stochastic control were compared. Achieved results of adaptive stochastic management were better than results provided by dispatcher graph and provide inspiration for continuing research in the field
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    Stochastic Management of the Open Large Water Reservoir with Storage Function with Using a Genetic Algorithm
    (IOP Publishing, 2016-09-05) Kozel, Tomáš; Starý, Miloš
    Described models are used random forecasting period of flow line with different length. The length is shorter than 1 year. Forecasting period of flow line is transformed to line of managing discharges with same length as forecast. Adaptive managing is used only first value of line of discharges. Stochastic management is worked with dispersion of controlling discharge value. Main advantage stochastic management is fun of possibilities. In article is described construction and evaluation of adaptive stochastic model base on genetic algorithm (classic optimization method). Model was used for stochastic management of open large water reservoir with storage function. Genetic algorithm is used as optimization algorithm. Forecasted inflow is given to model and controlling discharge value is computed by model for chosen probability of controlling discharge value. Model was tested and validated on made up large open water reservoir. Results of stochastic model were evaluated for given probability and were compared to results of same model for 100% forecast (forecasted values are real values). The management of the large open water reservoir with storage function was done logically and with increased sum number of forecast from 300 to 500 the results given by model were better, but another increased from 500 to 750 and 1000 did not get expected improvement. Influence on course of management was tested for different length forecasted inflow and their sum number. Classical optimization model is needed too much time for calculation, therefore stochastic model base on genetic algorithm was used parallel calculation on cluster.
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    The influence of different technologies of soil processing on infiltration properties of soil in the cambisols area of the Opava district
    (Mendel University in Brno, 2016-10-30) Dumbrovský, Miroslav; Larišová, Lucie
    The subject of the contribution is the evaluation of the influence of the conventional tillage and reduced tillage technology of soil processing on the infiltration properties of the soil in the Větřkovice area. Field experimental work at the area was carried out in the years 2013-2015 on Cambisol district medium-heavy clayey soil. The research was conducted on sloping erosion-endangered blocks of arable land sown with spring barley. The areas were chosen each year in the way that one of the experimental areas was handled by conventional tillage technologies and the other by reduced tillage technologies. Intact soil samples were taken into Kopecký's cylinders in the three landscape positions, at a depth of 10 cm (representing topsoil) and 30 cm (representing subsoil). The cumulative infiltration was measured using a mini-disc infiltrometer near the consumption points. The Zhang method (1997), which provides an estimate of the unsaturated hydraulic conductivity K(h), was used for the evaluation of the infiltration tests of the mini-disc infiltrometer. The soil profile processed by conventional tillage showed a higher degree of compaction. The bulk density was between 1.10-1.67 g.cm-3, compared to the land processed by the reduced tillage technology, where the values were between 0.80-1.29 g.cm-3. Unsaturated hydraulic conductivity values were about one-third higher within the reduced tillage technology soil processing.
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    Black Carbon and Its Effect on Carbon Sequestration in Soil
    (MDPI, 2021-11-09) Kopecký, Marek; Kolář, Ladislav; Váchalová, Radka; Konvalina, petr; Batt, Jana; Mráz, Petr; Menšík, Ladislav; Hoang, Trong Nghia; Dumbrovský, Miroslav
    The properties of black carbon (BC) are described very differently in the literature, even when determined by the same methodological procedure. To clarify this discrepancy, BC was investigated in the clay Cambisols of southern Bohemia, Czech Republic, in groups of soils with lower and higher deposition of its atmospheric fallout. The BC determination was performed according to a modified method of Kuhlbusch and Crutzen (1995). The amount of the free light fraction, the occluded light fraction of soil organic matter and its ratio, the amount of heavy soil fraction DF, and its soil organic matter DFOM were determined. Other soil characteristics were identified. It was found that there are two very different types of BC in soils. Historical BC from biomass fires, and new, anthropogenic, from the furnace and transport fumes. Historical BC has a significant effect on the organic matter of the heavy soil fraction, on the ratio of the free and occluded soil organic matter fraction, and the number of water-resistant soil aggregates. Anthropogenic BC does not have this effect. Because this form of BC is not significantly stabilized by the colloidal mineral fraction, it is necessary to take general data on BC's high stability and resistance to mineralization in the soil with circumspection.
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    Fractionation of Soil Organic Matter into Labile and Stable Fractions
    (MDPI, 2022-01-03) Kopecký, Marek; Kolář, Ladislav; Perná, Kristýna; Váchalová, Radka; Mráz, Petr; Konvalina, petr; Murindangabo, Yves Theoneste; Ghorbani, Mohammad; Menšík, Ladislav; Dumbrovský, Miroslav
    The present study aims to test and evaluate the efficiency of a new modified method of organic matter evaluation. It allows the assessment of the quality and quantity of the primary soil organic matter and the stable organic fractions separately. The new method was tested in six soil samples of different localities in the Czech Republic. This method is based on observing reaction kinetics during the oxidation of soil organic matter and measuring the cation-exchange capacity of stable organic fractions. The results were compared with classical methods, which rely on the isolation of humic substances, determination of the content of humic acids and fulvic acids and their ratio C-HA:C-FA, quotient E-4/6, and fractionation of soil organic matter according to resistance to oxidation. It turned out that the results of the new modified method are more sensitive in comparison with the results obtained by classical procedures. The linear regression demonstrated the dependence between the amounts of soil organic matter determined by the classical method compared with the modified method. Moreover, the new modified method was found to be faster and not demanding on laboratory equipment. The new method has been improved to be easily repeatable, and some shortcomings of the previous method were eliminated. Based on our results and other recent studies, the modified method may be recommended for the practical evaluation of soil organic matter conditions.