Nutrient concentrations in runoff from beef cattle feedlots were estimated using two different adaptive network-based fuzzy inference systems (ANFIS), which were: (1) grid partition (ANFIS-GP) and (2) subtractive clustering based fuzzy inference system (ANFIS-SC). The input parameters were pH and electrical conductivity (EC); and the output parameters were total Kjeldahl nitrogen (TKN), ammonium-N (NH4-N), orthophosphate (ortho-P), and potassium (K). Models performances were evaluated based on root mean square error, mean absolute error, mean bias error, and determination coeficient statistics. For the same dataset, the ANFIS model outputs were also compared with a previously published nutrient concentration predictability model for runoff using artificial neural network (ANN) outputs. Results showed that both ANFIS-GP and ANFIS-SC models successfully predicted the runoff nutrient concentration. The comparison results revealed that the ANFIS-GP model performed slightly better than ANFIS-SC model in estimating TKN, NH4-N, ortho-P, and K. When compared with the ANN model for the same dataset, ANFIS outperformed ANN in nutrient concentration prediction in runoff.
Error estimations arising from phase-wave fluctuations on laser beam propagation through turbulent atmosphere are given. The phase error value increases with the distance of satellite and is up to 8 cm for satellites with synchronous orbit in the daytime.
So far the photorespiration rate (RP) in a leaf has been determined as the difference between the net photosynthetic rates (PN) measured in 21 % O2 air (PN21%) and 3 % O2 air (PN3%). In the C3 plant Vigna radiata and the C4 plant Amaranthus mongostanus L., PN and chlorophyll fluorescence quenching in leaves were monitored simultaneously. RP of leaves in situ was estimated as termed RPE from the electron transport rates through photosystem 2 (PS2), and compared with RPO (PN3% - PN21%). In V. radiata RPO was 11.9 µmol(CO2) m-2 s-1 and the ratio of RPO to PN21% was 42.2 %, whereas the ratio of RPE to PN21% was 25.7 %. This suggests that RPO may be over-estimated for the real RP in normal air. In A. mongostanus, PN was almost not changed with a decrease in O2 concentration from 21 to 3 %, whereas the quantum yield of PS2 was evidently affected by the change in O2 concentration. This fact shows the presence of photorespiration in this C4 species, where RPE was equivalent to 3.8 % of PN21%. and Y. Yoshimura, F. Kubota, K. Hirao.
In order to evaluate the photosynthetic activity of a C3 leaf from the electron transport rate (ETR) of photosystem 2 (PS2), a new method was devised and examined using leaves of sweet potato. In this method, both surfaces of a leaf were sealed with transparent films to stop the gas exchange between the leaf and the atmosphere; hence the functions of both photosynthetic assimilation (CO2 uptake) and photorespiration (CO2 release) are restricted to the inside of the leaf. After both functional rates became equally balanced, ETR of the sealed leaf (ETRseal) was determined from the chlorophyll fluorescence. The measurements were conducted at different irradiances and leaf temperatures and by using leaves of different age. Under each measurement condition, ETRseal showed a close positive relationship with the photosynthetic potential, or the gross photosynthetic rate measured in the air of 2 % O2 (PG2%) before sealing. ETRseal may become an indicator to estimate or evaluate the photosynthetic activity of C3 leaves. and Haimeirong, F. Kubota, Y. Yoshimura.
Primary productivity in marine waters is widely estimated by the measurements of 14C incorporation, the underwater light climate, and the absorption spectra of phytoplankton. In bio-optical models the quantum efficiency of carbon fixation derived from 14C incorporation rates, the photosynthetically absorbed radiation derived from the underwater light climate, and the phytoplankton absorption spectra are used to calculate time- and depth-integrated primary productivity. Due to the increased sensitivity of commercially available fluorometers, chlorophyll a in vivo fluorescence became a new tool to assess the photosynthetic activity of phytoplankton. Since fluorescence data yield only relative photosynthetic electron transport rates, a direct conversion into absolute carbon fixation rates is not possible. Here, we report a procedure how this problem can be adressed in freshwater phytoplankton. We adapted a marine bio-optical model to the freshwater situation and tested if this model yields realistic results when applied to a hypertrophic freshwater reservoir. Comparison of primary productivity derived from 14C incorporation to primary productivity derived from Chl a fluorescence showed that the conversion of fluorescence data into carbon fixation rates is still an unsolved problem. Absolute electron transport rates calculated from fluorescence data tend to overestimate primary production. We propose that the observed differences are caused mainly by neglecting the package effect of pigments in phytoplankton cells and by non-carbon related electron flow (e.g., nitrogen fixation). On the other hand, the 14C incorporation rates can be artificially influenced by "bottle effects", especially near the water surface, where photoinhibition, photorespiration, and Mehler reaction can play a major role. and M. Gilbert ... [et al.].
Real time prediction of return periods of flood events that might occur in the course of anticipated dangerous meteorological situations at a catchment could be useful as additional information for decision makers involved in flood warning. Such a method is proposed in the paper for the Torysa basin in the western part of East Slovakia for rainfall-induced floods. A conceptual rainfall-runoff model with a daily time step was adopted for modelling of the runoff. The study of the relationship between the modelled basin’s soil moisture index at the beginning of the annual maximum floods and the flood-causing precipitation totals showed no dependence between these two quantities. Based on that finding, several scenarios involving the independent joint occurrence of synthetic extreme precipitation and antecedent basin saturation indexes were constructed. Using event-based flood simulations, synthetic flood waves were generated for these scenarios with the rainfall-runoff model. The relationships between the return periods of the synthetic precipitation and the return periods of the simulated floods were analysed, and the effect of antecedent basin saturation index on the extremity of the floods was quantified. Critical values of the basin saturation index leading to floods with higher return periods than the return period of flood-causing precipitation were suggested. A simple method of implementing such critical values into real time flood risk warnings in a hydrological forecasting and warning system in the Torysa basin was outlined. and Predpovedanie N-ročnosti povodní v reálnom čase pri výskyte kritických meteorologických situácií na povodiach je dôležité ako dodatočná informácia z hľadiska rozhodovacieho procesu v protipovodňovom varovnom systéme a následných opatreniach na povodiach. Táto štúdia bola preto zameraná na posudzovanie vzájomného pôsobenia extrémnych príčinných tekutých zrážok a rôznych stavov predchádzajúceho nasýtenia na pilotnom povodí Torysy po Prešov. Pre modelovanie odtoku na povodí bol použitý koncepčný zrážkovo-odtokový model s denným krokom. Pri výbere počiatočných podmienok vzniku povodní sme posudzovali rôzne stavy nasýtenia povodia pred vznikom najväčších ročných povodní, ktoré sa vyskytli na uvedenom povodí v minulosti. Na základe kombinácií modelových extrémnych príčinných zrážok s rôznymi stavmi predchádzajúceho nasýtenia povodia sme hydrologickým modelovaním simulovali odtok z povodia. Analyzoval sa vzťah medzi dobou opakovania modelových zrážok a simulovaných povodní a následne sa kvantifikoval vplyv predchádzajúceho nasýtenia povodia na extremitu odtoku. Určili sa kritické hodnoty nasýtenia povodia, kedy doba opakovania povodní prevyšuje hodnotu doby opakovania príčinných zrážok. Záverom bola navrhnutá jednoduchá metóda implementácie týchto kritických hodnôt pri predpovedaní povodní v reálnom čase na povodí Torysy.
At present days, the requirements on reliability analysis of power oil transformers are increasing in technical practice. Properly estimated reliability characteristics inform the user how to service machine, and such estimation also saves the user‘s financial means. In the first part of this paper, the models for estimating reliability characteristics only from a set of times to failure of power oil transformers are described. Additionally, the Cox model, which enables for such machines to complete reliability analysis with diagnostic measurements, is introduced. In the last part of this paper, the Cox model is enhanced by factor analysis and moreover, the acquired results are compared with real behaviour of tested power oil transformers during operation. and Obsahuje seznam literatury
This paper contains the studies of the noise level in GPS (Global Positioning System) time series. As the data for this research the authors used changes of the geodetic coordinates of the ASG-EUPOS and associated (Slovak and Czech) sites. The method of precise GPS observations processing in short-time intervals was worked out in the Centre of Applied Geomatics, Military University of Technology. The authors focus on the diurnal and sub-diurnal frequency bands (tidal) as the tidal effects influence the sites’ positions at the most and the model used in the standard processing software does not contain geodetic coefficients. Thus the residual values of the geodetic coordinates time series should hold some information in the shape of coloured noise. The paper comprise short description of the Earth tides phenomenon, the concept of the tidal parameters determination, character of the white and coloured noise and the assessment of the noise estimation from GPS data. As the processed network contains 130 sites the spatial distribution of the noise’s parameters is also investigated., Janusz Bogusz and Bernard Kontny., and Obsahuje bibliografii
Summary characteristics play an important role in the analysis of spatial point processes. We discuss various approaches to estimating summary characteristics from replicated observations of a stationary point process. The estimators are compared with respect to their integrated squared error. Simulations for three basic types of point processes help to indicate the best way of pooling the subwindow estimators. The most appropriate way depends on the particular summary characteristic, edge-correction method and also on the type of point process. The methods are demonstrated on a replicated dataset from forestry.
An estimation procedure for suspended sediment concentrations based on the intensity of backscattered sound of acoustic Doppler current profilers (ADCP) is introduced in this paper. Based on detailed moving and fixed boat ADCP measurements with concurrent sediment sampling, we have successfully calibrated the estimation method for a reach of River Danube in Hungary, characterized by significant suspended sediment transport. The effect of measurement uncertainty and various data filtering on sediment load determination is also analyzed and quantified. Some of the physical model parameters describing the propagation of sound in water are estimated based on known empirical formulas, while other parameters are derived from measured. Regression analysis is used to obtain a relationship between the intensity of backscattered sound and sediment concentrations. The empirical relationship has been then used to estimate the suspended sediment concentrations from the ADCP data collected in fixed and moving boat measurement operation mode, along verticals and path-lines, respectively. We show that while some measurement uncertainty is inherent to the acoustic Doppler principle, it is further enhanced by the complexity of the near-bottom sediment-laden flow. This uncertainty has then a significant effect on the local sediment load estimation. In turn, reasonable smoothing of raw velocity and backscatter intensity data shows insignificant impact on cross-sectional sediment load estimation.