Wyniki wyszukiwania - BazTech

1

Application of the Plackett-Burman Design on Soil Fertility Determinants

Mehdaoui Imane, El Ouadrhiri Faiçal, Saoudi Hassani El Mokhtar, Ben Abbou Mohamed, Elhaji Mounia, Akhazane Mohamed, Taleb Mustapha, Rais Zakia

Journal of Ecological Engineering

|

2022

|

Vol. 23, nr 12

254--263

EN

In the present review article, a soil from the region of Fez-Sefrou Morocco was screened for some physicochemical characteristics using the Plackett-Burman model in order to determine the most important factors that promote its fertility. Five independent variables were selected: pH, electrical conductivity, humidity, organic matter, and C/N ratio. These variables were evaluated by statistical analysis, based on their significance, the value of the coefficient of determination and the Pareto chart. The results suggest that humidity and C/N ratio have an influence with a high level of confidence, while the other three show no significant effect on the content of nutrients in the soil. The analysis of the R2 variance value also showed that the models used for prediction were large and significant factors (p less than 0.05). Pareto chart plots for each response and its characteristics provided accurate data to select well-fitting variables for further optimization.

2

The Ability of Peat in Adsorption of Biogenic Elements from Water Environment

Matsuska Oksana, Suchorska Olga, Gumnitsky Jaroslaw

Journal of Ecological Engineering

|

2020

|

Vol. 21, nr 4

224--230

EN

The possibilities of using a natural sorbent – peat for the wastewater treatment of ammonium ions and phosphates discharged from runoff into natural reservoirs at high concentrations were investigated. The peat of from the Vereshchytsya-Yanovske deposit of Ukraine of two depths: lowland and upland, was studied. It was established that the lowland samples of peat have higher sorption properties to the investigated pollutants from the aquatic environment than the upland ones. A greater moisture loss in the lowland peat species was observed, as well as the major part of the plant fibers in its structure, which explains its sorption properties. Due to the high content of humic substances, the extraction of cations from the water by peat can occur due to the ion exchange. The adsorption isotherms of both ammonium and phosphate ions on the top and lowland peat species of the Vereshchytsya-Yanovske deposit were constructed and presented. The adsorption isotherm obtained in the experimental studies was used to mathematically establish the isotherm equation, using the Langmuir and Freundlich models to describe the equilibrium of the sorption processes under study. The degree of appropriation of linear equations to the experimental data was evaluated on the basis of the deterministic coefficient, which enabled to determine that in each case the Langmuir equations describe the adsorption isotherms more adequately.

3

Wybrane zagadnienia aproksymacji charakterystyk statycznych termoanemometrów CTA

Olczyk A.

Prace Instytutu Mechaniki Górotworu PAN

|

2016

|

T. 18, nr 4

157--168

PL

W artykule przeanalizowano możliwości aproksymacji odwrotnych charakterystyk termoanemometrów stałotemperaturowych (CTA) za pomocą różnych funkcji. Porównano wyniki aproksymacji z wykorzystaniem funkcji wielomianowych (3-go i 4-go stopnia), wykładniczych (eksponencjalnej, Stirliga oraz Gompertza) a także funkcji potęgowej. Wykorzystując wskaźniki jakości aproksymacji (takie jak współczynnik determinacji czy błąd średniokwadratowy) dokonano ilościowej oceny poszczególnych metod na bazie trzech różnych zestawów danych pochodzących z rzeczywistych wzorcowań termoanemometrów.

EN

Possibilities of approximation of inverse static characteristics of constant temperature hot-wire anemometers, by means of different functions were analyzed in the paper. The results of approximation with use of polynomials (3rd and 4th degree), exponential functions (exponential growth, Stirling and Gompertz function) as well as power function were presented and compared. Applying some coeffi cients describing the quality of approximation (like coefficient of determination or mean squared error), quantitative evaluation of particular methods was done, on the basis of three different data sets, originating from real hot wire calibrations.

4

Identification of the best architecture of a multilayer perceptron in modeling daily total ozone concentration over Kolkata, India

De S.S., De B.K., Chattopadhyay G., Paul S., Haldar D.K., Chakrabarty D.K.

Acta Geophysica

|

2011

|

Vol. 59, no. 2

361-376

EN

Autoregressive neural network (AR-NN) models of various orders have been generated in this work for the daily total ozone (TO) time series over Kolkata (22.56°N, 88.5°E). Artificial neural network in the form of multilayer perceptron (MLP) is implemented in order to generate the AR-NN models of orders varying from 1 to 13. An extensive variable selection method through multiple linear regression (MLR) is implemented while developing the AR-NNs. The MLPs are characterized by sigmoid non-linearity. The optimum size of the hidden layer is identified in each model and prediction are produced by validating it over the test cases using the coefficient of determination (R²) and Willmott’s index (WI). It is observed that AR-NN model of order 7 having 6 nodes in the hidden layer has maximum prediction capacity. It is further observed that any increase in the orders of AR-NN leads to less accurate prediction.

5

Efficient online handwritten Chinese character recognition system using a two-dimensional functional relationship model

Chang Y. F., Lee J. C., Mohd Rijal O., Syed Abu Bakar S. A. R.

International Journal of Applied Mathematics and Computer Science

|

2010

|

Vol. 20, no 4

727-738

EN

This paper presents novel feature extraction and classification methods for online handwritten Chinese character recognition (HCCR). The X-graph and Y-graph transformation is proposed for deriving a feature, which shows useful properties such as invariance to different writing styles. Central to the proposed method is the idea of capturing the geometrical and topological information from the trajectory of the handwritten character using the X-graph and the Y-graph. For feature size reduction, the Haar wavelet transformation was applied on the graphs. For classification, the coefficient of determination [...] from the two-dimensional unreplicated linear functional relationship model is proposed as a similarity measure. The proposed methods show strong discrimination power when handling problems related to size, position and slant variation, stroke shape deformation, close resemblance of characters, and non-normalization. The proposed recognition system is applied to a database with 3000 frequently used Chinese characters, yielding a high recognition rate of 97.4% with reduced processing time of 75.31%, 73.05%, 58.27% and 40.69% when compared with recognition systems using the city block distance with deviation (CBDD), the minimum distance (MD), the compound Mahalanobis function (CMF) and the modified quadratic discriminant function (MQDF), respectively. High precision rates were also achieved.

6

Wielowariantowa metoda usuwania błędów grubych w eksploatacyjnych badaniach niezawodnościowych.

Godziszewski J.

Zagadnienia Eksploatacji Maszyn

|

2003

|

Vol. 38, nr 1

61-79

PL

Wskaźniki niezawodnościowe stanowią nader często dane wyjściowe do różnych zastosowań praktycznych. Efektywność ich wykorzystania uwarunkowana jest ich bezbłędnością. Eksploatacyjne badania niezawodnościowe ze względu na swą specyfikę stwarzają warunki do zaistnienia błędów grubych przy określaniu wartości czasów do uszkodzenia niektórych obiektów. Błędy te wpływają w istotny sposób na wartość wskaźników niezawodnościowych. Przedstawiono oryginalną metodę opartą na wieloetapowej procedurze sekwencyjnej, prowadzonej w oparciu o rachunek analizy korelacji i regresji, która pozwala na identyfikację i korekcję błędów grubych, o ile udział ich w próbce nie przekracza 20%. Metoda posiada trzy warianty, tj. eliminacyjny, eliminacyjno-korekcyjny i korekcyjny, które można dobrać do danego typu rozkładu najlepiej opisującego własności niezawodnościowe próbki. Jednocześnie sprawdzono, że obliczanie i porównywanie mocy korelacji dla danych wyjściowych pozwala na poprawną identyfikację typu rozkładu - nawet w przypadku występowania dużej liczby błędów grubych.

EN

Very often the initial data for various practical application tasks consists of reliability characteristics. Their effectiveness in use, however, depends on the extent to which they are error-free. At the same time, reliability field research, by its very nature, creates conditions for errors to occur when determining the life span of certain structures. Such errors have a vital influence on the value of the reliability characteristics. In this paper we introduce an original method for the identification and correction of gross errors, as long as they do not exceed 20% of the total sample. The method is based on a multistage sequential procedure carried out on the basis of a calculus of correlation analysis and regression. There are three variants of the method: eliminatory, eliminatory-corrective and corrective. These can be matched to the given type of distribution that best describes the reliability characteristics of the sample. At the same time, we have varied that the calculation and comparison of the coefficient of determination for the initial data allow for correct identification of the type of distribution, even in the case where a large number of errors occurs.