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Wyszukujesz frazę "Zhou, Z" wg kryterium: Autor


Tytuł:
Low to middle vibro-acoustic noise prediction in ship cabin by using plate-cavity coupling model
Autorzy:
Zhou, Z.
Wu, J.
Powiązania:
https://bibliotekanauki.pl/articles/260260.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
low to middle frequencies
vibration
ship noise
analysis model
rapid calculation method
Opis:
A plate-cavity coupling method based on modal expansion technique in the closed sound cavity was introduced, aiming at ship cabin structural noise. Using this method, a coupled equation was established. The structural vibration acceleration of the target cabin was extracted from a ship vibration response calculation, applied to the model. Then the target cabin noise value was obtained through numerical calculation. The effectiveness and reliability of the method were validated through experiments. The coupled model predicts noise in the cabin does not require fluid finite element model of the cabin air, thus greatly reducing the calculation time compared with the pure finite element method. It was shown that the method is suitable for the calculation of noise in a single ship cabin; the method has a high calculation efficiency. Furthermore, the calculated result is a continuum. On the one hand, it can be conveniently converted to an octave or 1/3 octave according to the specification. On the other hand, the form of the continuum also provides a corresponding response to the subsequent vibration and noise control.
Źródło:
Polish Maritime Research; 2018, S 2; 149-157
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on Community Garden Practice – Taking “the Kid’s Garden” in Hunan Agricultural University as an Example
Autorzy:
Zhou, Z.
Huang, Y.
Zhou, C.
Powiązania:
https://bibliotekanauki.pl/articles/1191265.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Przyrodniczy we Wrocławiu
Tematy:
community garden
Kid’s garden
urban agriculture
university support model
ogród społeczny
ogród dla dzieci
zieleń miejska
uniwersytecki model wsparcia
Chiny
Opis:
As a form of urban green space, community gardens have provided urban residents with various environments, to satisfy their social, economic and health interests. For the purposes of creating public, open and shared spaces, this article summarizes and contrasts the history of the community garden development in Europe and America, while analyzing the development situation of China as well. Taking “the Kid’s Garden” in Hunan Agricultural University as an example, the authors discuss the whole practice process in three aspects: the layout design, the construction process, and the operation and maintenance plan. Finally, the conclusion of the article presents a community garden building model, which is supported by universities with the goals to reward the society, as well as to provide a win-win result between practice and teaching. This experience is hoped to popularize community gardens and to make a contribution towards a harmonious society.
Źródło:
Architektura Krajobrazu; 2017, 3; 34-43
1641-5159
Pojawia się w:
Architektura Krajobrazu
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Seedling growth, root development and nutrient use efficiency of Cypress clones in response to calcium fertilizer
Autorzy:
Zhang, Z.
Jin, G.
Zhou, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2078194.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Cupressus funebris
root development
nutrient accumulation efficiency
calcium response
fertile
soil
low fertility soil
Opis:
Cypress (Cupressus funebris Endl.) is an important tree species in the subtropical regions of China; it is also a major tree species for afforestation and forest land restoration under low-fertility soil conditions. Cypress is considered a calcicolous tree, and its growth and development can be promoted significantly by exchangeable calcium (Ca2+) in the soil. However, most of the subtropical regions have low-fertility acidic soils, in which Ca2+ gradually becomes a limiting element for Cypress growth. In this study, different concentrations of Ca2+ fertilizer were added under fertile soil (3 g kg−1 NPK fertilizer added) and low-fertility soil (0 g kg−1 NPK fertilizer added) conditions. Cypress clones responded differently to Ca2+ addition in different soil conditions. The seedling height and dry matter quality of Cypress in fertile soil were significantly greater than those in low-fertility soil, but plant height and dry biomass did not differ significantly among Ca2+ treatments. The accumulation efficiencies of nitrogen (N), phosphorous (P) and Ca all differed significantly among the Ca2+ treatments. In low-fertility soil, the addition of 3 g kg-1 Ca2+ significantly promoted development of roots 0.5–2 mm in diameter, and both the C1 and C2 clones achieved their highest N, P and Ca accumulation efficiencies. When the Ca2+ concentration increased to 6 g kg−1, the seedling height, dry matter quality and root development were lower than those of the 3 g kg−1 Ca2+ treatment. In the fertile soil, the addition of Ca2+ significantly inhibited development of roots 0.5–1 mm in diameter. The highest N accumulation efficiency was achieved under the 0 g kg−1 Ca2+ treatment, and the highest Ca accumulation efficiency was achieved under the 6 g kg−1 Ca2+ treatment. Seedling height, root dry weight, roots 0–1.5 mm in diameter and Ca accumulation showed a significant interaction effect between NPK fertilizer and Ca2+. Therefore, Ca accumulation was more efficient in low-fertility soils. Under low-fertility soil conditions, the addition of CaSO4 can promote the root development of seedlings and advance and prolong the fast growth period of seedling height. Cypress clones can be used as an important tree species for afforestation under low-fertility soil conditions, especially under calcareous soil conditions.
Źródło:
Dendrobiology; 2020, 84
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Boiling, steaming or rinsing? (the physics of chinese cuisine)
Gotować, gotować na parze czy może płukać? (fizyka kuchni chińskiej)
Autorzy:
Varlamov, A.
Zhou, Z.
Chen, Y.
Powiązania:
https://bibliotekanauki.pl/articles/129558.pdf
Data publikacji:
2018
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
complex organic molecules
proteins
damplings
heat transfer
temperature conductivity
Fourier law
Newton's law of cooling
złożone molekuły organiczne
proteiny
kluski
przenoszenie ciepła
przewodnictwo temperaturowe
prawo Fouriera
Newtonowskie prawo chłodzenia
Opis:
Some physical aspects of Chinese cuisine are discussed. We start from the cultural and historical particularities of Chinese cuisine and their food production technologies. What is the difference between raw and boiled meat? What is the difference in the physical processes of heat transfer during either the steaming of dumplings or during cooking them in boiling water? Why is it possible to cook meat stripes in a "hot pot" in ten seconds, whilst baking a turkey requires several hours? This article is devoted to a discussion of these questions.
W artykule zostały przedyskutowane niektóre aspekty kuchni chińskiej. Autorzy zaczynają od omówienia szczegółów kuchni chińskiej i technologii produkcji żywności. Autorzy zadają następujące pytania: jaka jest różnica pomiędzy mięsem surowym a gotowanym? Jaka jest różnica w fizyce procesu przenoszenia ciepła podczas przyrządzania klusków na parze wodnej a w gotującej się wodzie? Dla czego jest możliwe przyrządzanie kawałków mięsa w "gorącym garnku" w ciągu kilku sekund, podczas gdy po to, aby upiec indyka potrzebujemy kilku godzin? Artykuł ten udziela odpowiedzi na te i inne pytania.
Źródło:
Physics for Economy; 2018, 2, No.1; 55-68
2544-7742
2544-7750
Pojawia się w:
Physics for Economy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimized design and analysis of offshore Beidou maritime foundation reinforcement system pseudolite ranging-codes
Autorzy:
Su, D.
Zhou, A.
Zhou, Z.
Chen, W.
Powiązania:
https://bibliotekanauki.pl/articles/260498.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
Beidou pseudolite
ranging-codes
optimized
3-taps
Opis:
Under the bad sea conditions and weak Beidou navigation signal environment, it is difficult to locate the ship on the sea, and the Beidou navigation system can’t work well. Beidou pseudolite system can improve the performance of Beidou navigation system as a navigation signal transmitter fixed on the ground, the signal of which can improve satellite positioning constellation structure, and improve the system availability reliability and precision. In order to ensure the interoperability and non-correlation of the Beidou pseudolite and the Beidou navigation system, the pseudolite ranging-codes should be selected in the same code space of the satellite ranging-codes and the residual pseudo random code generated by the 2 taps design scheme does not satisfy the performance requirements of the ranging-codes. To solve this issue, a combined design scheme with 3 taps is proposed, and 12 kinds of pseudolite ranging-codes are optimally selected according to the optimum design parameters of ranging-codes. The waveform and correlation of the selected pseudolite ranging-codes are analyzed by MATLAB, the acquisition simulation is carried out by using the new pseudolite ranging-codes. The experimental results show that the new 3-taps based ranging codes design scheme behaves a good balance, correlation and spectral characteristics.
Źródło:
Polish Maritime Research; 2017, S 2; 45-52
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Peridynamic analysis of 2-dimensional deformation and fracture based on an improved technique of exerting traction on boundary surface
Autorzy:
Zhou, Z.
Yu, M.
Wang, X.
Huang, Z.
Powiązania:
https://bibliotekanauki.pl/articles/38695705.pdf
Data publikacji:
2022
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
peridynamics
peridynamic motion equation
adaptive dynamic relaxation
traction boundary conditions
Opis:
For 2-dimensional problems in peridynamics, the transfer functions of boundary traction are constructed. The peridynamic motion equation introducing the boundary traction is improved and used to solve some typical 2-dimensional deformation and fracture problems, including the uniaxial tension and pure bending of plate, and fracture of a plate with the small circular hole or central crack. The acquired numerical solutions are close to the analytical solutions of elasticity and numerical solutions given by the finite element method. The results show that the improved technique of exerting traction on a boundary surface is valid for calculating the deformation and failure of solid. It provides a new method and path for the analysis of traction boundary value problems in peridynamics.
Źródło:
Archives of Mechanics; 2022, 74, 6; 441-461
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New bird remains from the Middle Eocene of Guangdong, China
Autorzy:
Wang, M.
Mayr, G.
Zhang, J.
Zhou, Z.
Powiązania:
https://bibliotekanauki.pl/articles/21279.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
new taxon
bird
remains
Middle Eocene
Guangdong Province
China
Aves
Ciconiiformes
Threskiornithidae
Eocene
fossil record
fossil bird
paleontology
Sanshuiornis zhangi
Huayong Formation
Opis:
We describe a new avian taxon (Sanshuiornis zhangi gen. et sp. nov.) from Middle Eocene black oil shales in the Huayong Formation of Guangdong Province, south China. The specimen consists of a distal tibiotarsus and a complete foot with tarsometatarsus and pedal digits in articulation. A preliminary phylogenetic analysis does not resolve the affinities of the fossil, but the bones show resemblances to some “ciconiiform” birds. The peculiar hypotarsus morphology, which is block−like and exhibits four cristae, resembles that of the early Eocene Rhynchaeites, which is a stem group representative of the Threskiornithidae. The new Chinese fossil has, however, proportionally longer legs than Rhynchaeites and its phylogenetic affinities probably cannot be resolved without further material.
Źródło:
Acta Palaeontologica Polonica; 2012, 57, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Image encryption combining discrete fractional angular transform with Arnold transform in image bit planes
Autorzy:
Zhou, Z.
Yu, J.
Liao, Q.
Gong, L.
Powiązania:
https://bibliotekanauki.pl/articles/173704.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Arnold transform
bit plane
discrete fractional angular transform
image encryption algorithm
Opis:
A new image encryption algorithm by using a discrete fractional angular transform and Arnold transform in image bit planes is investigated. In the image encryption algorithm, the original image is encrypted by the Arnold transform in image bit planes firstly, and then the resulting image is encrypted by the discrete fractional angular transform further. The key of the image encryption algorithm includes the parameters of the Arnold transform and the order of the discrete fractional angular transform. It is shown that the proposed image encryption algorithm is of high security and strong enough to counteract some conventional image attack manners.
Źródło:
Optica Applicata; 2018, 48, 2; 225-236
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Near-field multiple optical trapping using high order axially symmetric polarized beams
Autorzy:
Zhou, Z
Tan, Q
Zhu, L
Yang, C
Powiązania:
https://bibliotekanauki.pl/articles/174886.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
optical trapping
surface plasmon polaritons
axially symmetric polarized beams
Opis:
The near-field multiple optical trapping using high order axially symmetric polarized beams (ASPBs) is studied for the first time. First, a near-field optical trapping scheme is proposed based on the Kretschmann–Raether configuration, and surface plasmon polaritons (SPPs) field distributions excited by incident ASPBs are calculated, which present a multi-focal-spot pattern and the size of spots is much smaller than that of the diffraction limitation. Then, the gradient forces on Rayleigh dielectric particles formed by the multi-focal-spot focused field are computed, which indicates that multiple ultra-small particles with the refractive index higher than that of the ambient medium can be trapped simultaneously on the metal surface. The number and size of trapped particles can be manipulated by flexibly modifying the polarization order of incident beams, which is expected to enhance the capability of traditional optical trapping systems and provide a solution for massively parallel optical trapping of nanometer-sized particles.
Źródło:
Optica Applicata; 2013, 43, 2; s. 287-296
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Image encryption algorithm by using the logistic map and discrete fractional angular transform
Autorzy:
Yu, J.
Li, Y.
Xie, X.
Zhou, N.
Zhou, Z.
Powiązania:
https://bibliotekanauki.pl/articles/173813.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
image encryption
logistic map
discrete fractional angular transform
Opis:
A new image encryption scheme based on logistic map and discrete fractional angular transform has been proposed. In the proposed scheme, the original image is encrypted with the random sequence generated by the logistic map, and the encrypted image is subsequently processed by the discrete fractional angular transform, which produces the ciphertext after double encryptions. The parameters of the logistic map and the order of the discrete fractional angular transform serve as the main keys of the image encryption algorithm. Simulation results show that the proposed image encryption algorithm can effectively resist the attacks of statistical analysis, and has acceptable encryption effect and security.
Źródło:
Optica Applicata; 2017, 47, 1; 141-155
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Provenance-specific climate sensitivity of Pinus massoniana – a multi-environmental trial in subtropical China
Autorzy:
Zhang, Z.
Jin, G.
Feng, Z.
Sun, L.
Zhou, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2078265.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Pinus massoniana
provenance
climate change
wood density
radial growth
Opis:
Climate change is causing changes in tree species performance and distribution, impacting breeding programme effectiveness. Our aim was to analyse the effects of provenance and climatic factors on the annual ring density of Masson pine (Pinus massoniana Lamb.) at different experimental sites and potential breeding strategies that may be developed in response to future climate change. The study trees represented provenances originating from the western, east-central, northern, and southern regions of P. massoniana distribution in China. The wood density differed significantly among provenances. A multisite variance analysis test showed that the type B correlation coefficients for ring density at the two sites stud- ied were less than 0.8, indicating an interaction effect of genotype by environment (G×E) on tree ring density. Climatic factors directly affected the wood density properties. At Chun’an (CA), the maximum latewood density (MXD) and minimum earlywood density (MND) were positively correlated with absolute maximum temperatures in August and May of the current growing season, respectively. At Taizi Mountain (TZS), MXD was significantly positively correlated with absolute maximum temperature in September of the current year and significantly negatively correlated with precipitation in June. MND was significantly positively correlated with absolute maximum temperature in May of the current year and significantly negatively correlated with precipitation in April. The climatic effects on P. massoniana wood density differed among seed-source origins. This study showed that ring density characteristics differed significantly among provenances, and provenance selection could promote wood density. MXD and MND exhibited significant genotype-by-environment interaction effects, and significant correlations were found between ring density and temperature and precipitation conditions. These findings suggest that climatic factors and site condi- tions in addition to genetics could be strong drivers of wood density variation, and/or that wood density is a highly plastic trait.
Źródło:
Dendrobiology; 2021, 85; 3-18
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural Stabilities and Elastic Constants of EuX (X = O, S, Se, and Te) Compounds at High Pressure
Autorzy:
Kong, B.
Zhou, Z.
Sun, X.
Zhang, L.
Ling-Hu, R.
Powiązania:
https://bibliotekanauki.pl/articles/1400144.pdf
Data publikacji:
2013-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.66.-f
46.70.-p
61.43.-j
75.50.-y
Opis:
The structural stabilities, elastic properties and charge transfers of EuX (X = O, S, Se, Te) compounds as a function of pressure are investigated extensively using first-principles calculations. The ground-state parameters, such as lattice constants, bulk modulus are predicted and compared with the available data, our results are satisfactory. The calculated phase transition pressures from the NaCl-type (B1) structure to the CsCl-type (B2) structure for EuX (X = O, S, Se, Te) also accord with the experiments. Particularly, the elastic constants of EuX (X = O, S, Se, Te) under zero pressure and high pressure are simulated appropriately for the first time via density functional theory. The softening behaviors of the elastic shear modulus $C_{44}$ under pressure for the B1 phase of EuX (X = O, S, Se, Te) are captured, which should be responsible for the pressure-induced structural phase transition in the EuX system. It is also suggested that the softening behavior might be induced partly by the p → d and f → d electron transfers of Eu atom under pressure. In addition, the aggregate elastic modulus (B, G, E), Poisson's ratio (σ), Debye temperature $\Theta p_{D}$ are also successfully obtained for both B1 and B2 phases of EuX.
Źródło:
Acta Physica Polonica A; 2013, 123, 4; 720-727
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameter Description of the Surface Metal Fiber Arrangement of Electromagnetic Shielding Fabric
Wpływ rozmieszczenia włókien metalowych na skuteczność ekranowania tkanin osłonowych
Autorzy:
Liu, Z.
Su, Y.
Pan, Z.
Li, Y.
Wang, X.
Zhou, Z.
Powiązania:
https://bibliotekanauki.pl/articles/232915.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
electromagnetic shielding fabric
surface metal fiber blends
surface metal arrangement
tkanina ekranująca
tkanina osłonowa elektromagnetyczna
układ metalowy powierzchni
Opis:
The influence of the surface metal fiber (SMF) arrangement on the shielding effectiveness (SE) of electromagnetic shielding fabric (EMSF) is important, but there is no reasonable description method for it at present, making the further exploration of the relationship between SMF and SE difficult. In order to scientifically describe the SMF arrangement of EMSF, this paper constructs a binary feature matrix of SMF based on a previous study of SMF region recognition. According to the feature matrix, three parameters of the exposure ratio, the discrete mean and disorder degree are proposed and the calculation equations for the three parameters given. Experiments were designed and testing samples determined to test the SE, and the exposure ratio, discrete mean and disorder degree of each sample are calculated. The relationship between the three parameters and the SE is analysed for effectiveness validation of the three parameters. Results show that the exposure ratio, discrete mean and disorder degree can describe three aspects of the SMF arrangement: the percentage content, porosity and orientation, which are positively correlated, negatively correlated and positively correlated to the SE, respectively. The research in this paper provides a basis for the study of the shielding mechanism, the transmission model, the shielding rule and the rapid non-destructive evaluation of the EMSF, and puts forward a new idea for the study of shielding theory and the application of the EMSF.
Ze względu na istotny wpływ rozmieszczenia włókien metalowych (SMF) na skuteczność ekranowania (SE) tkanin osłonowych (EMSF) w pracy przedstawiono macierz binarną opartą na trzech parametrach włókien metalowych tj.: współczynniku ekspozycji, średniej wartości odległości między włóknami metalowymi i stopniu ich nieuporządkowania. Analizowano zależności pomiędzy wyżej wymienionymi parametrami a skutecznością ekranowania. Przedstawione wyniki stanowią podstawę do opracowania szybkiej i nieniszczącej metody oceny skuteczność ekranowania oraz do dalszych badań mechanizmu ekranowania.
Źródło:
Fibres & Textiles in Eastern Europe; 2017, 2 (122); 62-67
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A planning model for the chemical integrated system under uncertainty by grey programming approach
Autorzy:
Ren, J.
Tan, S.
Dong, L.
Zhou, Z.
Gao, S.
Pan, C.
Powiązania:
https://bibliotekanauki.pl/articles/778898.pdf
Data publikacji:
2013
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
planning
chemical integrated system
grey programming
Opis:
A model to optimize the planning of the chemical integrated system comprised by multi-devices and multi-products has been proposed in this paper. With the objective to make more profits, the traditional model for optimizing production planning has been proposed. The price of chemicals, the market demand, and the production capacity have been considered as mutative variables, then an improved model in which some parameters are not constant has been developed and a new method to solve the grey linear programming has been proposed. In the grey programming model, the value of credibility can be suggested by the decision-makers, and the results of the production planning calculated by the model can help them to achieve their desired target. An actual case has been studied by the proposed methodology, and the proposed methodology can be popularized to other cases.
Źródło:
Polish Journal of Chemical Technology; 2013, 15, 2; 16-22
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An improved feature extraction method for rolling bearing fault diagnosis based on MEMD and PE
Autorzy:
Zhang, H.
Zhao, L.
Liu, Q.
Luo, J.
Wei, Q.
Zhou, Z.
Qu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/259770.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
improved feature extraction method
rolling bearing fault diagnosis
MEMD
PE
Opis:
The health condition of rolling bearing can directly influence to the efficiency and lifecycle of rotating machinery, thus monitoring and diagnosing the faults of rolling bearing is of great importance. Unfortunately, vibration signals of rolling bearing are usually overwhelmed by external noise, so the fault frequencies of rolling bearing cannot be readily obtained. In this paper, an improved feature extraction method called IMFs_PE, which combines the multivariate empirical mode decomposition with the permutation entropy, is proposed to extract fault frequencies from the noisy bearing vibration signals. First, the raw bearing vibration signals are filtered by an optimal band-pass filter determined by SK to remove the irrelative noise which is not in the same frequency band of fault frequencies. Then the filtered signals are processed by the IMFs_PE to get rid of the relative noise which is in the same frequency band of fault frequencies. Finally, a frequency domain condition indicator FFR(Fault Frequency Ratio), which measures the magnitude of fault frequencies in frequency domain, is calculated to compare the effectiveness of the feature extraction methods. The feature extraction method proposed in this paper has advantages of removing both irrelative noise and relative noise over other feature extraction methods. The effectiveness of the proposed method is validated by simulated and experimental bearing signals. And the results are shown that the proposed method outperforms other state of the art algorithms with regards to fault feature extraction of rolling bearing.
Źródło:
Polish Maritime Research; 2018, S 2; 98-106
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł

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