Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "REGRESSION ANALYSIS" wg kryterium: Wszystkie pola


Wyświetlanie 1-9 z 9
Tytuł:
Application of multiple linear regression (MLR) analysis for concentration of chromite tailings by the flotation
Autorzy:
Deniz, Vedat
Powiązania:
https://bibliotekanauki.pl/articles/1449296.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
chromite
tailing
flotation
separation
multiple linear regression analysis
Opis:
In this study, the concentration of chromite minerals by amine flotation of a chromite tailing (slime) with content 23.84% Cr2O3 from Yeşilova-Burdur (Turkey) was investigated. In experimental studies, firstly, some operating parameters of the rougher flotation observed for a low-grade chromite tailing were investigated. Secondly, multiple linear regression (MLR) analyses were performed to determine the effects of some operating parameters on the performance of the rougher amine flotation. From the experimental results, multiple linear regression equations were developed to predict the recovery and grade of the chromite concentrate, and the regression coefficients between experimental and predicted values were found to be quite good (R2 values of 0.772 and 0.917, respectively). Additionally, it was found that the conditioning time and low pH value using $H_2SO_4$ showed an important effect on the recovery and the grade of the chromite concentrate.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 4; 579-589
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of the lower calorific and ash values of the lignite coal by using artificial neural networks and multiple regression analysis
Autorzy:
Gulec, Mahmut
Gulbandilar, Eyyup
Powiązania:
https://bibliotekanauki.pl/articles/109973.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
lignite chemical analyses
artificial neural networks
Seyitomer lignite
Tuncbilek lignite
Opis:
The calorific value of coal varies depending on type of coal and foreign matter content. The calorific value of coal from pits is determined by analyzing moisture, volatile matter, ash and sulfur content in laboratories. This analysis process imposes a burden on businesses both in terms of time and cost. However, calorific value, in particular, can be determined through simpler methods by using ash and moisture values. The aim of this study was to develop a model that reduces the time and labor costs of coal companies by determining the calorific value and ash content of coal with the back-propagation algorithm of artificial neural networks (ANN). The model design was developed based on the data that was obtained from the laboratory analyses of raw coals from the pits of Tuncbilek and Seyitomer mining areas in Turkey. The values of moisture, volatile matter, original ash and sulfur were determined as input variables, and the lower calorific values and ash content were selected as output variables. The lower calorific values (LCV) and Ash estimated by the developed model were compared with the LCV obtained in the laboratory tests and the results showed a correlation. In addition, two different ANN models and multiple regression analysis (MRA) were developed to obtain the single output of the LCV and ash parameters with similar features. As a result, the ANN model and MRA equation models proposed in this study was shown to successfully estimate the LCV and ash content of coals without performing laboratory analyses.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 2; 400-406
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinematic determinants of weapon velocity during the fencing lunge in experienced épée fencers
Autorzy:
Bottoms, L.
Greenhalgh, A.
Sinclair, J.
Powiązania:
https://bibliotekanauki.pl/articles/307476.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fencing
kinematics
lunge
regression analysis
velocity
kinematyka
płuca
prędkość
biomechanika
Opis:
The lunge is the most common attack in fencing, however there is currently a paucity of published research investigating the kinematics of this movement. The aim of this study was to investigate if kinematics measured during the épée fencing lunge had a significant effect on sword velocity at touch and whether there were any key movement tactics that produced the maximum velocity. Lower extremity kinematic data were obtained from fourteen right handed club épée fencers using a 3D motion capture system as they completed simulated lunges. A forward stepwise multiple linear regression was performed on the data. The overall regression model yielded an Adj R2 of 0.74, p ≤ 0.01. The results show that the rear lower extremity’s knee range of motion, peak hip flexion and the fore lower extremity’s peak hip flexion all in the sagittal plane were significant predictors of sword velocity. The results indicate that flexion of the rear extremity’s knee is an important predictor, suggesting that the fencer sits low in their stance to produce power during the lunge. Furthermore it would appear that the magnitude of peak flexion of the fore extremity’s hip was a significant indicator of sword velocity suggesting movement of fore limbs should also be considered in lunge performance.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 4; 109-113
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Approximation and Prediction of the Wind Speed Change Function
Autorzy:
Klen, K.
Zhuikov, V.
Powiązania:
https://bibliotekanauki.pl/articles/410602.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
distributed generation
wind generator
Heisenberg’s uncertainty principle
linear approximation
Walsh functions
regression analysis
Opis:
In the article the features of energy summation from two wind generators, located at a certain distance from each other, are considered. The method of calculating the correlation function between the wind flow speed change functions in the direction of wind distribution is presented. The formulas for describing the fluctuation components of energy at the output of the wind generator are given for two cases: when the phases of the fluctuations of the wind flow on two wind generators are the same and when the fluctuations of the wind flow are in the antiphases. It is shown that to increase the energy level that can be taken from the wind power plant it is necessary to control the phase shift between the energy fluctuations at the output of the wind generators and use the energy of the storages; and to use linear approximations to approximate the wind speed change function. Under the condition of a linear change of the internal resistance of the wind generator in time, it is advisable to introduce the wind speed change function with linear approximations. The system of orthonormal linear functions based on Walsh functions is given. A table with formulas and graphs describing the first 8 functions, which are arranged in order of increasing the number of their sign alternating on the interval of functions definition, is presented. The result of the approximation of the wind speed change function with a system of 8 linear functions based on Walsh functions is shown. Decomposition coefficients, mean-square and average relative approximation errors for such approximation are calculated. In order to find the parameters of multiple linear regression the method of least squares is applied. The regression equation in matrix form is given. An example of application of linear regression prediction method to simple functions is shown. The restoration result for wind speed change function is shown. Decomposition coefficients, mean-square and average relative approximation errors for restoration of wind speed change function with linear regression method are calculated.
Źródło:
Present Problems of Power System Control; 2018, 9; 35-46
2084-2201
Pojawia się w:
Present Problems of Power System Control
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of process parameters for composting of pulp/paper mill sludge with hazelnut kernel using a statistical method
Autorzy:
Aycan, N.
Turan, N. G.
Ozgonenel, O.
Powiązania:
https://bibliotekanauki.pl/articles/207046.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
algorithms
composting
regression analysis
ANOVA test
optimization algorithms
optimization of process parameters
algorytmy
kompostowanie
analiza regresji
Test ANOVA
algorytmy optymalizacji
optymalizacja parametrów technologicznych
Opis:
An effective way to remove ammonium from compost using hazelnut kernels (HK) has been presented. The role of experimental factors on the removal of ammonium was examined by using the full factor experimental design (FFED). The experimental factors and their related levels were selected as time of 1-6 weeks, moisture of 50-70%, and HK amendment ratio of 5-25. The results were then evaluated by the ANOVA test to examine importance of the process variables (inputs) and their levels. A regression model taking into account main significant and interaction effects was suggested. According to the optimization algorithm, time of 5 weeks, moisture of 50%, and HK amendment ratio of 25 with the removal capacity of 60% were selected as optimum levels. The proposed analyzing procedure is simple to implement and cost-effective.
Źródło:
Environment Protection Engineering; 2014, 40, 1; 127-138
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chemical characterization and source identification of particulate matter PM 10 in a rural and urban site in Poland
Autorzy:
Samek, L.
Zwoździak, A.
Sówka, I.
Powiązania:
https://bibliotekanauki.pl/articles/207766.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
rozwój miast
emisja pyłów
analiza regresji
pyły
tereny miejskie
tereny wiejskie
koncentracja pyłów
pyły zawieszone w powietrzu
urban growth
particulate emissions
regression analysis
particulate matter
urban sites
rural sites
Opis:
The measurements of PM 10 at two sites in Poland - a typical village and a big city considered urban background - indicated only a small difference in PM 10 concentrations. In summer time, the concentrations ofPMlO did not exceed the daily limit value of 50 jig/rn3 while in wintertime, the daily limit value was exceeded for almost all sampling days for both sites. Source contributions to ambient PM 10 were determined with factor analysis (FA) and multilinear regression analysis (MLRA) based on PM1O composition data including concentrations of K, Ca, Ti, Cr, Mn, Fe, Cu, Zn, Br, Pb and As. In the winter, local combustion sources contributed with 61% and 79% to total mass in the urban and rural sites, respectively, reflecting serious local or even regional problem associated with PMIO pollution. The episodic presence of As, the commonly known toxic element, requires a detailed study for better understanding of its temporal distribution both in the rural and urban atmosphere.
Źródło:
Environment Protection Engineering; 2013, 39, 4; 91-103
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multivariate analysis of 200-m front crawl swimming performance in young male swimmers
Autorzy:
Nasirzade, A.
Sadeghi, A.
Sobhkhiz, A..
Mohammadian, K.
Nikouei, A.
Baghaiyan, M.
Fattahi, A.
Powiązania:
https://bibliotekanauki.pl/articles/306342.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
regresja krokowa
antropometria
pływanie
sport
stepwise regression
stroke length
anthropometry
fascicle length
front crawl
Opis:
The aim of the present study was to evaluate the biomechanical (stroke rate, stroke length, and stroke index), anthropometrical (body height, body mass, body mass index, arm span, shoulders width, thigh, leg and upper arm lengths), and muscle architectural (muscle thickness, pennation angle, and fascicle length) parameters as predictors of 200-m front crawl swimming performance in young male swimmers. Twenty-two county level male swimmers (mean ±SD: age: 14.52 ± 0.77 years; body height: 173 ± 5 m; body mass: 60.5 ± 5.7 kg) performed a 200-m front crawl swimming test in a 25-m pool. Stepwise regression analysis revealed that biomechanical parameters (87%) characterized best 200-m front crawl swimming performance, followed by anthropometrical (82%) and muscle architectural (72%) parameters. Also, stroke length (R2 = 0.623), body height (R2 = 0.541), fascicle length of Triceps Brachii (R2 = 0.392) were the best single predictors that together explained 92% of the variability of the 200-m front crawl swimming performance in these swimmers. As a conclusion, with respect to higher performance prediction power of biomechanical parameters, technique should represent the core of the training program at these ages. In addition, these findings could be used for male young swimmers selection and talent identification.
Źródło:
Acta of Bioengineering and Biomechanics; 2015, 17, 3; 137-143
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling the determinants of winning in public tendering procedures based on the activity of a selected company
Autorzy:
Malara, M.
Mazurkiewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/406605.pdf
Data publikacji:
2012
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
binary logistic regression
discriminant analysis
public procurement law
public procurement
procedures
Opis:
The purpose of this article is to identify the factors influencing the probability of winning in public procurement procedures and to assess the strength of their impact from the perspective of both: the bidder and procurer. The research was conducted with the use of series of quantitative methods: binary logistic regression, discriminant analysis and cluster analysis. It was based on a sample consisting of public tenders, in which the examined company performed the role of a bidder. Thus, the research process was aimed at both identifying the factors of success and estimating the probability of achieving it, where it was possible to obtain probabilities. The main idea of this research is to answer questions about the utility of various methods of quantitative analysis in the case of analyzing determinants of success. Results of the research are presented in the following sequence of sections: characteristics of the examined material, the process of modelling the probability of winning, evaluation of the quality of the results obtained.
Źródło:
Operations Research and Decisions; 2012, 22, 1; 51-62
2081-8858
2391-6060
Pojawia się w:
Operations Research and Decisions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Occupational composition of an economy and effective retirement age across European countries: an econometric analysis
Autorzy:
Chybalski, Filip
Powiązania:
https://bibliotekanauki.pl/articles/2175849.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
retirement age
occupation
human resources
policy decision
regression
simulation
Opis:
In this study, panel regression models for 21 European countries and data covering the period between 2008 and 2014 were used to demonstrate that the distribution of working population across different occupational groups explains cross-country differences in terms of the average effective retirement age. Thus, while the great majority of previous studies verified the causal trade-off investigated on the basis of single-country micro data with reference to one economy, this study takes perspective of cross-country diversity in terms of the investigated relationship. The confirmed link holds even when controlling inter alia for health status, education, unemployment, old-dependency ratio, interest rate, GDP per capita, or the share of salaries and wages in GDP. An important practical implication for the policy-makers is that decisions limited only to the increase in the universal pensionable age cannot be effective, since the occupational composition of an economy is very relevant.
Źródło:
Operations Research and Decisions; 2022, 32, 3; 65--79
2081-8858
2391-6060
Pojawia się w:
Operations Research and Decisions
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-9 z 9

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies