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Tytuł:
Application of fuzzy type II multi-layer Kalman filter for parameters identification of two-mass drive system
Autorzy:
Śleszycki, Kacper
Wróbel, Karol
Szabat, Krzysztof
Katsura, Seiichiro
Powiązania:
https://bibliotekanauki.pl/articles/27311447.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
electrical drives
torsional vibration
state estimation
Kalman filter
multi-layer estimator
napędy elektryczne
drgania skrętne
ocena stanu
estymator wielowarstwowy
filtr Kalmana
Opis:
The paper describes a novel online identification algorithm for a two-mass drive system. The multi-layer extended Kalman Filter (MKF) is proposed in the paper. The proposed estimator has two layers. In the first one, three single extended Kalman filters (EKF) are placed. In the second layer, based on the incoming signals from the first layer, the final states and parameters of the two-mass system are calculated. In the considered drive system, the stiffness coefficient of the elastic shaft and the time constant of the load machine is estimated. To improve the quality of estimated states, an additional system based on II types of fuzzy sets is proposed. The application of fuzzy MKF allows for a shorter identification time, as well as improves the accuracy of estimated parameters. The identified parameters of the two-mass system are used to calculate the coefficients of the implemented control structure. Theoretical considerations are supported by simulations and experimental tests.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 4; art. no. e146107
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Developing a data-driven soft sensor to predict silicate impurity in iron ore flotation concentrate
Autorzy:
Pural, Yusuf Enes
Powiązania:
https://bibliotekanauki.pl/articles/24148677.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
soft sensor
machine learning
random forest
multi-layer perceptron
flotation
grade estimation
Opis:
Soft sensors are mathematical models that estimate the value of a process variable that is difficult or expensive to measure directly. They can be based on first principle models, data-based models, or a combination of both. These models are increasingly used in mineral processing to estimate and optimize important performance parameters such as mill load, mineral grades, and particle size. This study investigates the development of a data-driven soft sensor to predict the silicate content in iron ore reverse flotation concentrate, a crucial indicator of plant performance. The proposed soft sensor model employs a dataset obtained from Kaggle, which includes measurements of iron and silicate content in the feed to the plant, reagent dosages, weight and pH of pulp, as well as the amount of air and froth levels in the flotation units. To reduce the dimensionality of the dataset, Principal Component Analysis, an unsupervised machine learning method, was applied. The soft sensor model was developed using three machine learning algorithms, namely, Ridge Regression, Multi-Layer Perceptron, and Random Forest. The Random Forest model, created with non-reduced data, demonstrated superior performance, with an R-squared value of 96.5% and a mean absolute error of 0.089. The results suggest that the proposed soft sensor model can accurately predict the silicate content in the iron ore flotation concentrate using machine learning algorithms. Moreover, the study highlights the importance of selecting appropriate algorithms for soft sensor developments in mineral processing plants.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 5; art. no. 169823
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Handling high and low priority traffic in multi-layer networks
Autorzy:
Biernacka, Edyta
Boryło, Piotr
Jurkiewicz, Piotr
Wójcik, Robert
Domżał, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/27311464.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
elastic optical resources
high priority traffic
multi-layer networks
priority-aware bypasses
sieci wielowarstwowe
obejście uwzględniające priorytety
ruch priorytetowy
zasób optyczny elastyczny
Opis:
In this paper, we propose a novel priority-aware solution named bypass to handle high- and low-priority traffic in multi-layer networks. Our approach assumes diversification of elastic optical spectrum to ensure additional resources reserved for emergency situations. When congestion occurs, the solution dynamically provides new paths, allocating a hidden spectrum to offload traffic from the congested links in the IP layer. Resources for a bypass are selected based on traffic priority. High-priority traffic always gets the shortest bypasses in terms of physical distance, which minimizes delay. Bypasses for low-priority traffic can be established if the utilization of the spectrum along the path is below the assumed threshold. The software-defined networking controller ensures the global view of the network and cooperation between IP and elastic optical layers. Simulation results show that the solution successfully reduces the amount of rejected high-priority traffic when compared to regular bypasses and when no bypasses are used. Also, overall bandwidth blocking probability is lower when our priority-aware bypasses are used.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 3; art. no. e145568
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of sound absorption performance of acoustic absorbers made of fibrous materials
Autorzy:
Meissner, Mirosław
Zieliński, Tomasz G.
Powiązania:
https://bibliotekanauki.pl/articles/2202433.pdf
Data publikacji:
2022
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
sound absorption
multi-layer absorber
surface impedance
fibrous materials
air gap
chłonność akustyczna
wielowarstwowy pochłaniacz dźwięku
materiały włókniste
szczelina powietrzna
Opis:
Absorbing properties of multi-layer acoustic absorbers were modeled using the impedance translation theorem and the Garai and Pompoli empirical model, which enables a determination of the characteristic impedance and propagation constant of fibrous sound-absorbing materials. The theoretical model was applied to the computational study of performance of single-layer acoustic absorber backed by a hard wall and the absorber consisting of one layer of absorbing material and an air gap between the rear of the material and a hard back wall. Simulation results have shown that a high thickness of absorbing material may cause wavy changes in the frequency relationship of the normal and random incidence absorption coefficients. It was also found that this effect is particularly noticeable for acoustic absorbers with a large thickness of air gap between the absorbing material and a hard back wall.
Źródło:
Vibrations in Physical Systems; 2022, 33, 2; art. no. 2022205
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Water Quality Index and Multivariate Statistical Techniques to Assess and Predict of Groundwater Quality with Aid of Geographic Information System
Autorzy:
Dawood, Ammar S.
Jabbar, Mushtak T.
Al-Tameemi, Hayfaa H.
Baer, Eric M.
Powiązania:
https://bibliotekanauki.pl/articles/2105290.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
cluster analysis
water quality
groundwater
factor analysis
WQI
GIS
multi-layer perceptron
Opis:
In this study, the groundwater quality and spatial distribution of the Basra province in the south of Iraq was assessed and mapped for drinking and irrigation purposes. Groundwater samples (n = 41) were collected from deep wells in the study area to demonstrate, estimate and model the Water Quality Index (WQI). The analysis of water samples integrated with GIS-based IDW technique was used to express the spatial variation in the study area with consideration of WQI. The physicochemical parameters, including pH, sodium (Na+), electrical conductivity (EC), chloride (Cl-), total dissolved solids (TDS), calcium (Ca2+), nitrate (NO3-), sulfate (SO42-), magnesium (Mg2+), and bicarbonate (HCO3-) were identified for groundwater quality assessment. The results of calculated WQI classify groundwater into three sorts. The results of WQI showed that 2.5%, 2.5% and 95% of the groundwater samples were classified as poor/very poor/unsuitable for drinking, respectively. The GIS tools integrated with statistical techniques are utilized for spatial distribution and description of water quality. Correlation analysis of groundwater data revealed that some parameters have actually a relationship that is strong with the other parameters and they share a common source of origin. Multivariate statistical techniques, especially cluster analysis (CA) and factor analysis (FA), were applied for the evaluation of spatial variations of forty-one selected groundwater samples. Cluster analysis confirmed that some different locations of wells have comparable sourced elements of water pollution, whereas factor analysis yielded three factors which are accountable for groundwater quality variations, clarifying more than 72% of the total variance of the data and permitted to group the preferred water quality. MultiLayer Perceptron (MLP) models were applied in modeling the water quality index. Comparing different result values of the MLP network suggested that the values of MSE and r for the selected model are 0.1940 and 0.9998, respectively. Finally, it can be revealed that the MLP network precisely predicted the output, i.e. the WQI values.
Źródło:
Journal of Ecological Engineering; 2022, 23, 6; 189--204
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application perspective of digitalneural networks in the context of marine technologies
Autorzy:
Konon, V.
Konon, N.
Powiązania:
https://bibliotekanauki.pl/articles/24201415.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
marine technology
multi-layer perceptron
neural networks
digital neural networks
maritime industry
MLP algorithm
3D model
Artificial Neural Network
Opis:
This study is focused on the issue of digital neural networks’ implementation in the context of maritime industry. Various algorithms of such networks in the terms of the marine technologies have been reviewed in the current study in order to evaluate the effectiveness of the methodology and to propose a new concept of an artificial neural network’s application in this way. Fire-detection system simulation based on the thermal imagers’ data input had been developed to assess the efficiency of the concept suggested with a multi-layer perceptron (MLP) algorithm integrated into the designed 3d-model.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2022, 16, 4; 743--747
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characteristics of stress distribution of a multi layered cylindrical pressure vessel
Autorzy:
Somadder, Somnath
Das, Palash
Islam, Md. Ashraful
Powiązania:
https://bibliotekanauki.pl/articles/2201648.pdf
Data publikacji:
2022
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
stress distribution
thermo-mechanical load
multi-layer pressure vessels
centripetal
centrifugal
analytical analysis
numerical analysis
rozkład naprężeń
obciążenie termomechaniczne
wielowarstwowe naczynia ciśnieniowe
analiza analityczna
analiza numeryczna
Opis:
The operation of a multilayer pressure vessel subjected to thermomechanical loads is very significant. The cylindrical pressure vessel is widely used in industrial engineering: for example, to hold a variety of different types of liquid. On thick-walled cylinders, various loading circumstances such as internal overpressure, external overpressure, heat, bending, twisting, and combinations of these load characteristics are applied. Researchers have developed a number of strategies for enhancing the strength of cylinders, including the use of multilayer cylinders and increasing the thickness of the walls. This paper presents the results of an analytical and numerical analysis of a three-layer cylinder. The Abaqus FEA software is used to determine temperature, displacement, and stress distribution of a multilayer cylinder considering the effect of centripetal and centrifugal heat flow. From the numerical analysis, it is observed that centrifugal heat flux is more hazardous than centripetal heat flux for a multi-layered cylinder under thermo-mechanical loading.
Źródło:
Journal of Mechanical and Energy Engineering; 2022, 6, 2; 1--6
2544-0780
2544-1671
Pojawia się w:
Journal of Mechanical and Energy Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of a neural statistical model for the prediction of relative humidity levels in the region of Rabat-Kenitra, North West Morocco
Autorzy:
El Azhari, Kaoutar
Abdallaoui, Badreddine
Dehbi, Ali
Abdalloui, Abdelaziz
Zineddine, Hamid
Powiązania:
https://bibliotekanauki.pl/articles/2174362.pdf
Data publikacji:
2022
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
artificial neural network
ANN
learning algorithm
multi-layer perceptron
MLP
modelling
Rabat-Kenitra
relative humidity
Opis:
This article accounts for the development of a powerful artificial neural network (ANN) model, designed for the prediction of relative humidity levels, using other meteorological parameters such as the maximum temperature, minimum temperature, precipitation, wind speed, and intensity of solar radiation in the Rabat-Kenitra region (a coastal area where relative humidity is a real concern). The model was applied to a database containing a daily history of five meteorological parameters collected by nine stations covering this region from 1979 to mid-2014. It has been demonstrated that the best performing three-layer (input, hidden, and output) ANN mathematical model for the prediction of relative humidity in this region is the multi-layer perceptron (MLP) model. This neural model using the Levenberg-Marquard algorithm, with an architecture of [5-11-1] and the transfer functions Tansig in the hidden layer and Purelin in the output layer, was able to estimate relative humidity values that were very close to those observed. This was affirmed by a low mean squared error (MSE) and a high correlation coefficient (R), compared to the statistical indicators relating to the other models developed as part of this study.
Źródło:
Journal of Water and Land Development; 2022, 54; 13--20
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conversion of compression test data into flow curve, accounting for barrelling
Autorzy:
Khoddam, Shahin
Hodgson, Peter D.
Powiązania:
https://bibliotekanauki.pl/articles/29520227.pdf
Data publikacji:
2021
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
compression test
flow curve identification
barrelling induced shear
multi-layer
slab analysis
Opis:
Current solutions to convert the axis-symmetric compression test (ACT) data to flow data ignore the barrelling deformation in the sample. This work presents a solution for the test which accounts for the sample’s barrelling by discretising it into a finite number of layers of different radii. The solution assumes a constant and sliding friction at the anvil-sample interface. The sample’s flow behaviour is identified by combining a recent kinematic solution of the test, Prandtl–Reuss–Mises’s equations and a slab-analysis of the layers. It also involves an averaging of the effective plastic stresses developed in the individual layers. The solution is verified for a special case of no-barrelling which matches the currently used solution.
Źródło:
Computer Methods in Materials Science; 2021, 21, 3; 157-162
2720-4081
2720-3948
Pojawia się w:
Computer Methods in Materials Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An analysis of selected traits of typical supply of oak logs and a comparison of the efficiency of their processing into flooring
Autorzy:
Rębkowski, Bartłomiej
Koczan, Grzegorz
Kozakiewicz, Paweł
Krzosek, Sławomir
Powiązania:
https://bibliotekanauki.pl/articles/2200218.pdf
Data publikacji:
2020
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
wood raw material
European oak wood
wood flooring
multi-layer parquet elements
X-ray computed tomography
Opis:
An analysis of selected traits of typical supply of oak logs and a comparison of efficiency of their processing into flooring. The research was performed on typical supply of oak wood logs of WC02 class, diameter from 29 to 34 cm, measured in the middle of its length (full log length 2.3 m). Wood came from Bobolice forest district, Lubowo forest subdistrict. This type of raw wood is used in standard machining processes (sawing) of multi-layer flooring face layer (top layer, lamella). The application of X-ray computed tomography allows to perform full valuation of raw material quality. The introduction of partially chip-less machining technology leads to significant savings in wood in comparison with standard machining (sawing).
Analiza wybranych cech typowej dostawy kłód dębowych oraz porównanie wydajności ich przerobu na materiały podłogowe. Badania przeprowadzono na drewnie dębowym WC02 o średnicy w połowie długości bez kory od 29 do 34 cm i długości 2,3 m z Nadleśnictwa Bobolice, Leśnictwa Lubowo (reprezentatywny surowiec). Tego typu surowiec jest stosowany w standardowej technologii obróbki wiórowej przy wytwarzaniu warstw licowych (lameli) desek warstwowych. W pracy przeanalizowano jak wpłynęłaby na wydajność ilościową, zamiana technologii na częściowo bezwiórową. Zastosowanie obróbki częściowo bezwiórowej pozwala na zaoszczędzenie znaczących ilości surowca. Straty przy obróbce częściowo bezwiórowej w odniesieniu do całej kłody dębowej mogą być o ok. 15 punktów procentowych niższe niż w przypadku obróbki wiórowej. W odniesieniu do pryzmy różnica wielkości strat może wynosić nawet do 31 punktów procentowych. Sama analiza ilościowa nie daje odpowiedzi o celowości wprowadzania nowej technologii, bowiem nie uwzględnia wielu czynników np.: energochłonności obróbki hydrotermicznej niezbędnej przy skrawaniu. Równie istotna jest jakość pozyskiwanych lameli dębowych, co było przedmiotem analiz w innej pracy.
Źródło:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology; 2020, 109; 92--102
1898-5912
Pojawia się w:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Concrete grade change in the layers of three-layer steel fibre reinforced concrete beams
Autorzy:
Lam, T. Q. K.
Do, T. M. D.
Ngo, V. T.
Nguyen, T. T. N.
Pham, D. Q.
Powiązania:
https://bibliotekanauki.pl/articles/1818828.pdf
Data publikacji:
2020
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
steel fibre concrete
stress-strain
crack
material nonlinear
multi-layer beams
concrete grade
beton
włókno stalowe
naprężenie-odkształcenie
pęknięcie
materiał nieliniowy
belki wielowarstwowe
klasa betonu
Opis:
Purpose: Determine the state of stress-strain, formation and development cracks, three-layer beam diagrams of load-compression stress, load-tension stress, load-vertical displacement relationships with a change in concrete grade. Design/methodology/approach: This paper presents the results of an ANSYS numerical simulation analysis involving stress-strain state and cracking of the steel fiber concrete layers of three-layer reinforced concrete beams with the upper and lower layers. With a cross-section of 150x300 mm, a total span of 2200 mm and an effective length of 2000 mm, the middle is a normal concrete layer. Under two-point loads, all the beam samples were tested. The research simulated three-layer concrete beams in different layers of beams with a change in concrete grade, and compared with and without the use of steel fibers in layers of concrete beams, including the nonlinearity of the material considered. Findings: A diagram of the formation and development of cracks in three-layer concrete beams has been constructed by the study results, determining the load at which the concrete beams begin to crack, the load at which the concrete beams are damaged. In the middle of three-layer steel fiber reinforced concrete beams, load-compression stress, loadtension stress, load-vertical displacement relationships are established. Study results show that these three-layer concrete beams appear to crack earlier than in other cases in cases 2 and 3, but the beam bearing capacity is damaged at 67 kN, the earliest in case 3. And case 6 at 116 kN is the latest. The effects of case 1 and case 3 are small compared with and without the use of steel fibers in cases, while the effects of case 5 and case 6 are very high. Research limitations/implications: The research focuses only on the change of concrete grade in the layers, but the input parameters affecting three-layer steel fiber concrete beams have not been researched, such as the number of tensile steel bars, tensile steel bar diameter, steel fiber content in concrete, thickness variation in three-layer concrete beam layers, etc. Practical implications: Provides a result of experimental study and ANSYS numerical simulation in multi-layer steel fiber concrete beams. Originality/value: The analysis of multi-layered steel fiber concrete beams using experimental and simulation methods shows that other parameters influencing the beams will continue to analysis the working stages of three-layer beams.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2020, 102, 1; 16--29
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rakushechny Yar site: lacustrine and fluvial deposits, buried soils and shell platforms from 6th mill. BC
Autorzy:
Dolbunova, Ekaterina
Szmańda, Jacek
Kittel, Piotr
Kulkova, Marianna
Aleksandrovskiy, Alexander
Cywa, Katarzyna
Mazurkevich, Andrey
Powiązania:
https://bibliotekanauki.pl/articles/1366033.pdf
Data publikacji:
2020-12-24
Wydawca:
Łódzkie Towarzystwo Naukowe
Tematy:
Neolithic
flood-plain multi-layer site
sedimentology
buried soils
shell platforms
Opis:
The Rakushechny Yar site is a floodplain multi-layer archaeological site encompassing strata dated from the Early Neolithic to the Bronze Age. It is characterised by a complex stratigraphy, with the presence of different deposits, buried soils and archaeological layers. Fluvial deposits interlay different settlement strata, which provides an opportunity to elaborate a precise chronological scheme and to study the successive changes in hydrological regime, climate and vegetation, along with the phases of human occupation. A study of the pastes used in ceramic manufacture was conducted to investigate changes in the procuring of raw materials, whose procurement would have depended heavily on their availability and sedimentation process. The fluvial deposits, which have safely preserved the Neolithic–Bronze Age archaeological layers, reach thicknesses of more than 6 m, which makes this site interesting both for the reconstruction of the human–environmental interaction and for the palaeoenvironmental history of the region.
Źródło:
Acta Geographica Lodziensia; 2020, 110; 61-80
0065-1249
Pojawia się w:
Acta Geographica Lodziensia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic fire risk prevention strategy in underground coal gasification processes by means of artificial neural networks
Dynamiczna strategia zapobiegania ryzyku pożarowemu z użyciem sztucznych sieci neuronowych w procesach podziemnego zgazowania węgla
Autorzy:
Krzemień, Alicja
Powiązania:
https://bibliotekanauki.pl/articles/218921.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dynamiczna strategia zapobiegania ryzyku
prewencja ryzyka pożarowego
podziemne zgazowanie węgla (PZW)
dynamic alarm strategy
fire risk prevention
Generalized Regression Neural Network
Multi-Layer Feedforward Networks (MLFN)
Multivariate Adaptative Regression Splines (MARS)
underground coal gasification (UCG)
Opis:
Based on data collected during an UCG pilot-scale experiment that took place during 2014 at Wieczorek mine, an active mine located in Upper Silesia (Poland), this research focuses on developing a dynamic fire risk prevention strategy addressing underground coal gasification processes (UCG) within active mines, preventing economic and physical losses derived from fires. To achieve this goal, the forecasting performance of two different kinds of artificial neural network models (generalized regression and multi-layer feedforward) are studied, in order to forecast the syngas temperature at the georeactor outlet with one hour of anticipation, thus giving enough time to UCG operators to adjust the amount and characteristics of the gasifying agents if necessary. The same model could be used to avoid undesired drops in the syngas temperature, as low temperature increases precipitation of contaminants reducing the inner diameter of the return pipeline. As a consequence the whole process of UGC might be stopped. Moreover, it could allow maintaining a high temperature that will lead to an increased efficiency, as UCG is a very exothermic process. Results of this research were compared with the ones obtained by means of Multivariate Adaptative Regression Splines (MARS), a non-parametric regression technique able to model non-linearities that cannot be adequately modelled using other regression methods. Syngas temperature forecast with one hour of anticipation at the georeactor outlet was achieved successfully, and conclusions clearly state that generalized regression neural networks (GRNN) achieve better forecasts than multi-layer feedforward networks (MLFN) and MARS models.
Przedstawione w niniejszej pracy badania koncentrują się na opracowaniu dynamicznej strategii zapobiegania ryzyku pożarowemu w procesach podziemnego zgazowania węgla (PZW) w czynnych kopalniach. Celem badań jest zapobieganie ekonomicznym i fizycznym stratom wynikającym z pożarów. W pracy wykorzystano dane zebrane podczas pilotowego eksperymentu podziemnego zgazowania węgla, który odbył się w 2014 r. w czynnej Kopalni Węgla Kamiennego „Wieczorek”, zlokalizowanej na Górnym Śląsku. W artykule przeanalizowano działanie dwóch różnych modeli sztucznych sieci neuronowych, tj. sieci neuronowych realizujących uogólnione regresje GRNN oraz wielowarstwowych sieci perceptronowych MLFN, w celu prognozowania temperatury gazu syntezowego na wyjściu z georeaktora z godzinnym wyprzedzeniem. Informacja na temat temperatury na godzinę „do przodu” daje wystarczająco dużo czasu operatorowi procesu PZW na dostosowanie ilości i właściwości czynników zgazowujących do zaistniałej sytuacji. Ten sam model można zastosować do uniknięcia niepożądanych spadków temperatury gazu syntezowego. Niska temperatura gazu sprzyja wytrącaniu się osadu (substancji smolistych), powodując zmniejszanie średnicy rurociągu odbioru gazu, co w konsekwencji może prowadzić do całkowitego zatrzymania procesu zgazowania. Model pozwala również na utrzymanie wysokiej temperatury, która prowadzi do zwiększonej wydajności procesu PZW, szczególnie biorąc pod uwagę, że PZW jest procesem bardzo egzotermicznym. Wyniki zrealizowanych badań porównano z rezultatami uzyskanymi za pomocą modelu MARS – nieparametrycznej metody regresji zdolnej do modelowania zależność nieliniowych, których nie można odpowiednio modelować przy użyciu innych metod regresji. Prognoza temperatury gazu na godzinę „do przodu” na wylocie georeaktora została osiągnięta z powodzeniem, a wnioski jasno pokazują, że sieci neuronowe realizujące uogólnione regresje (GRNN – Generalized Regression Neural Networks) osiągają lepsze rezultaty niż wielowarstwowe sieci jednokierunkowe (MLFN – Multi-Layer Feedforward Networks) i modele MARS (Multivariate Adaptative Regression Splines).
Źródło:
Archives of Mining Sciences; 2019, 64, 1; 3-19
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fabrication and Macroscopic Properties of Filler Metal (BCuP-5) on Cu-plate using Laser Cladding Process
Autorzy:
Lee, Kee-Ahn
Park, Joo Hyun
Joo, Yeun Ah
Powiązania:
https://bibliotekanauki.pl/articles/352063.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
laser cladding
BCuP-5(Cu-15Ag-5P)
microstructure
switching device
multi-layer
Opis:
This study stacked a thin, dense BCuP-5 (Cu-Ag-P based filler metal) on a Cu-plate using the laser cladding (L.C) process to develop a method to manufacture Ag reducing multilayer clad electrical contact material with an Ag-M(O)/Ag/Cu/BCuP-5 structure. Then, the microstructure and macroscopic properties of the manufactured BCuP-5 coating layer were analyzed. The thickness of the manufactured coating layer was approximately 1.7 mm (maximum). Microstructural observation of the coating layer identified Cu, Ag and Cu-Ag-Cu3P ternary eutectic phases like those in the initial BcuP-5 powder. To evaluate the properties of the manufactured coating layer, hardness and adhesion strength tests were performed. The average hardness of the laser cladded coating layer was 183.2 Hv, which is 2.6 times greater than conventional brazed BcuP-5. The average pull-off strength measured using the stud pull test was 341.6 kg/cm2. Cross-sectional observation of the pulled-off material confirmed that the coating layer and substrate maintained a firm adhesion after pull-off. Thus, the actual adhesion strength of Cu/BcuP-5 was inferred to be greater than 341.6 kg/cm2. Based on the above findings, it was confirmed that it is possible to manufacture a sound Ag reducing multilayer clad electrical contact material using the laser cladding process.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 2; 559-563
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of stresses and strains in two-layer combined materials at their formation
Autorzy:
Koloskova, G. M.
Powiązania:
https://bibliotekanauki.pl/articles/379456.pdf
Data publikacji:
2019
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
computational material science and mechanics
multi-layer combined material
stress and strain modelling
calendering method
komputerowa nauka o materiałach
wielowarstwowy materiał łączony
modelowanie naprężeń i odkształceń
Opis:
Purpose: The aim of the represented study was to model the behaviour of two-layer combined material during its manufacturing. Design/methodology/approach: The model of material layers joining by means of calender method is built in LS-DYNA software on the basis of finite element method. Using the developed model the study of stress and strain condition changes is carried out. Numerical modelling was carried out for two types of two-layer combined materials in similar conditions. First combination was of high-density polyethylene top layer and aluminium foil bottom layer. Second combination was of high-density polyethylene top layer and low- density polyethylene bottom layer. Joining materials had equal thicknesses. Findings: During formation of two-layer combined materials the primary strain always occurs at the bottom plate of the bottom layer. However, the maximum plastic strain will be represented for the layer with lower elastic modulus value. At the point of the highest loading applied to the two-layer combined material the elasticity condition is changed to the plasticity one and the yield process is registered. Practical implications: Multi-layer combined materials are some of the most advanced types of materials. The quality of the joining of the layers, the strains and the stresses arising in their manufacturing process are the main causes of low interlayer strength. It leads to easy exfoliation and destruction of the material. The results of the study may be used to improve the quality of multi-layer combined materials. Originality/value: For the first time the model was developed for the determination of strains and stresses arising during the formation of multi-layer combined materials by means of calendering method. The calculations of the stresses and strains distribution dynamics for two-layer combined materials are represented for polymer-metal and polymer-polymer layers combinations. The results of the study may be of interest to specialists in the field of multi-layer combined materials designing and manufacturing.
Źródło:
Archives of Materials Science and Engineering; 2019, 97, 1/2; 12-19
1897-2764
Pojawia się w:
Archives of Materials Science and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
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