Informacja

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

Wyszukujesz frazę "Liu, Lin-Lin" wg kryterium: Autor


Tytuł:
Experimental study on vibration of a rotating pipe in still water and in flow
Autorzy:
Geng, Xinge
Wu, Weiguo
Liu, Erpeng
Lin, Yongshui
Chen, Wei
Rheem, Chang-Kyu
Powiązania:
https://bibliotekanauki.pl/articles/32916494.pdf
Data publikacji:
2023
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
flow-induced vibration
rotating pipe
vibration frequency
whirl
VIV
Opis:
To illustrate the vibration characteristics of a rotating pipe in flow, experiments were conducted for a pipe in flow, a rotating pipe in still water and a rotating pipe in flow. For the pipe in flow without rotation, the trajectory diagram is ‘8’ shaped. For the rotating pipe in still water, a multiple frequency component was induced, and a ‘positive direction whirl’ was found. For the flow and rotation, at a flow velocity of 0.46 m/s, the vibration is dominated by the combination of flow and rotation. With an increase in rotating frequency, the trajectory of the rotating pipe varies from an ‘8’ shape to a circular shape and the ‘reverse direction whirl’ is induced, which is different from ‘positive direction’ in still water. The vibration frequency ratio increases uniformly with flow velocity. At a flow velocity of 1.02 m/s, at which the frequency is close to the theoretical natural frequency, the vibration frequency ratio is f*≈1. Predominantly governed by vortex-induced vibration (VIV), the vibration behavior of a rotating pipe subjected to fluid flow conditions has been found to exhibit complete vanishing of whirl. The vibration characteristics of a rotating pipe in flow are studied by the experiments which is benefit for structural drilling design.
Źródło:
Polish Maritime Research; 2023, 1; 65-77
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Temporal and spatial heterogeneity of the Ailaoshan–Song Ma–Song Chay ophiolitic mélange, and its significance on the evolution of Paleo-Tethys
Autorzy:
Lin, Wei
Liu, Fei
Wang, Ying
Meng, Lingtong
Faure, Michel
Chu, Yang
Nguyen, Vuong Van
Wu, Qinying
We, Wei
Thu, Hoai Luong Thi
Vu, Tich Van
Powiązania:
https://bibliotekanauki.pl/articles/24202127.pdf
Data publikacji:
2023
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
Tethys
heterogeneity
Vietnam
Opis:
The ophiolite is the direct evidence to restore the oceanic evolution, and it is used to identify the convergence boundary of the plates. Compared with ophiolite, ophiolitic mélange, especially its matrix, contains more information about the evolution of ocean. The evolution of eastern Paleo-Tethys, between the South China and Indochina blocks, recorded the whole process of rifting from Gondwana and their northward migration and convergence. To understand the tectonic implications from matrix of ophiolitic mélange, the Mesozoic Paleo-Tethys Ailaoshan–Song Ma–Song Chay suture zone located in the North Vietnam–Southeast Yunnan region acts as an ideal study area. Based on the structural geology, we reviewed previous zircon U-Pb dating and Lu-Hf isotopic analyses on the detrital zircon from the Ailaoshan–Song Ma–Song Chay ophiolitic mélange. Accordingly, we subdivide the matrix of these ophiolitic mélange into four parts (M1, M2, M3, and M4; Fig. 1). M1 is mainly located in the middle segment of the Ailaoshan–Song Ma belt. It shows age peaks of 440 Ma and 960 Ma with εHf(t) values of −19.6 ~ +10.3. M2 is mainly located in the NW segment of the Ailaoshan–Song Ma belt, showing a dominant age peak of ~260 Ma. Particularly, it has εHf(t) values of −28.9 ~ +8.1. M3 is mainly located in the SE segment of the Ailaoshan–Song Ma belt, showing the peaks at ~250 Ma, 440 Ma, and 960 Ma with εHf(t) values of −21.9 ~ +10.1. M4 is mainly located in the Song Chay belt, showing the peaks at ~310 Ma, 470 Ma, 610 Ma, 770 Ma, and 965 Ma with εHf(t) values of −28.2 ~ +10.8. The geochronological data of the detrital zircon from the matrix of the Ailaoshan– Song Ma–Song Chay ophiolitic mélange zone, documents a temporal heterogeneity between the M1, M2, M3, and M4 units, which formed at 310–270 Ma, 265–250 Ma, 245–240 Ma, and 310–255 Ma, respectively. The different components and provenances of each unit reflect a strike-parallel heterogeneity (Fig. 1). The M1 unit was mainly sourced from the Paleozoic sedimentary rocks of the Indochina Block (IB). The main provenance for the M2 unit is Emeishan Large Igneous Province (ELIP). The magmatic arc developed in the IB provided the materials for the M3 unit, and the detrital materials of the M4 were mainly sourced from the South China Block (SCB) (Fig. 1). The Cenozoic strike-slip deformation led to an inverted geometry of the M1, M2, and M3 units, accounting for a strike-perpendicular heterogeneity straight to the strike of the orogenic belt. The temporal, strike-parallel, and strike-perpendicular heterogeneity help us to decipher the tempo-spatial evolution of the Paleo-Tethys. The M1, M2, M3, and M4 units contain information from different evolutionary stages, likely recording the comprehensive history of the ancient oceanic basin. Importantly, our results demonstrate that both the active continental margin of the IB and the passive continental margin of the SCB acted as provenance sources that supplied significant amount of detrital material in the ophiolitic mélange matrix, indicating that the Paleo-Tethys Ocean was a “narrow” or “limited” ocean rather than the archipelagic ocean proposed before.
Źródło:
Geotourism / Geoturystyka; 2023, 1-2 (72-73); 42--43
1731-0830
Pojawia się w:
Geotourism / Geoturystyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A machine learning method for soil conditioning automated decision-making of EPBM : hybrid GBDT and Random Forest Algorithm
Autorzy:
Lin, Lin
Guo, Hao
Lv, Yancheng
Liu, Jie
Tong, Changsheng
Yang, Shuqin
Powiązania:
https://bibliotekanauki.pl/articles/2087007.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
soil conditioning
automated decision-making
hybrid algorithm
geological parameters
drive parameters
feature selection
Opis:
There lacks an automated decision-making method for soil conditioning of EPBM with high accuracy and efficiency that is applicable to changeable geological conditions and takes drive parameters into consideration. A hybrid method of Gradient Boosting Decision Tree (GBDT) and random forest algorithm to make decisions on soil conditioning using foam is proposed in this paper to realize automated decision-making. Relevant parameters include decision parameters (geological parameters and drive parameters) and target parameters (dosage of foam). GBDT, an efficient algorithm based on decision tree, is used to determine the weights of geological parameters, forming 3 parameters sets. Then 3 decision-making models are established using random forest, an algorithm with high accuracy based on decision tree. The optimal model is obtained by Bayesian optimization. It proves that the model has obvious advantages in accuracy compared with other methods. The model can realize real-time decision-making with high accuracy under changeable geological conditions and reduce the experiment cost.
Źródło:
Eksploatacja i Niezawodność; 2022, 24, 2; 237--247
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new method for decision making problems with redundant and incomplete information based on incomplete soft sets: From crisp to fuzzy
Autorzy:
Xia, Sisi
Chen, Lin
Liu, Siya
Yang, Haoran
Powiązania:
https://bibliotekanauki.pl/articles/2172131.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
decision-making
soft set
incomplete fuzzy soft set
incomplete information
redundant information
podejmowanie decyzji
zbiór miękki
informacja niepełna
informacja zbędna
Opis:
This research is focused on decision-making problems with redundant and incomplete information under a fuzzy environment. Firstly, we present the definition of incomplete fuzzy soft sets and analyze their data structures. Based on that, binary relationships between each pair of objects and the “restricted/relaxed AND” operations in the incomplete fuzzy soft set are discussed. After that, the definition of incomplete fuzzy soft decision systems is proposed. To reduce the inconsistency caused by the redundant information in decision making, the significance of the attribute subset, the reduct attribute set, the optimal reduct attribute set and the core attribute in incomplete fuzzy soft decision systems is also discussed. These definitions can be applied in an incomplete fuzzy soft set directly, so there is no need to convert incomplete data into complete one in the process of reduction. Then a new decision-making algorithm based on the above definitions can be developed, which can deal with redundant information and incomplete information simultaneously, and is independent of some unreliable assumptions about the data generating mechanism to forecast the incomplete information. Lastly, the algorithm is applied in the problem of regional food safety evaluation in Chongqing, China, and the corresponding comparison analysis demonstrates the effectiveness of the proposed method.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2022, 32, 4; 657--669
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental research on the volatilization and condensation of ammonium bisulfate as SCR byproduct
Autorzy:
Jiao, Kunling
Ma, Shuangchen
Chen, Xiangyang
Liu, Jiaming
Qiao, Lin
Powiązania:
https://bibliotekanauki.pl/articles/2174830.pdf
Data publikacji:
2022
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Ammonium bisulfate
ABS
influencing factors
volatilization rate
condensation pattern
Opis:
In this paper, the research progress of ammonium bisulfate (ABS) volatilization in coal-fired power plants the SCR denitrification process was reviewed. Combination with self-made experiments, SEM, flue gas analyzer and TG-DTG curves of ABS and ion chromatography. The volatilization and condensation characteristics of ABS were investigated carefully. Results show that as the temperature increased by 50 °C, the ABS/AS volatilization rate increased by an order of magnitude. The decomposition process of ABS should have a two-step reaction. The reaction in the initial volatilization stage is ABS dehydration turned into (NH4)2S2O7. The reaction in the rapid volatilization stage is (NH4)2S2O7 decomposed into NH3, N2, SO2 and H2O. There is an inter-section in the reac-tion temperature range (especially 300 °C) between the two-step reaction. This research provides an experimental basis for temperature control of ABS to avoid air pre-heater fouling.
Źródło:
Polish Journal of Chemical Technology; 2022, 24, 4; 30--38
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
RFID tag group recognition based on motion blur estimation and YOLOv2 improved by Gaussian algorithm
Autorzy:
Li, Lin
Yu, Xiao-Lei
Liu, Zhen-Lu
Zhao, Zhi-Min
Zhang, Ke
Zhou, Shan-Hao
Powiązania:
https://bibliotekanauki.pl/articles/2051852.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
RFID
YOLOv2
neural network
GRNN
Opis:
Effective recognition of tags in the dynamic measurement system would significantly improve the reading performance of the tag group, but the blurred outline and appearance of tag images captured in motion seriously limit the effectiveness of the existing tag group recognition. Thus, this paper proposes passive tag group recognition in the dynamic environment based on motion blur estimation and improved YOLOv2. Firstly, blur angles are estimated with a Gabor filter, and blur lengths are estimated through nonlinear modelling of a Generalized Regression Neural Network (GRNN). Secondly, tag recognition based on YOLOv2 improved by a Gaussian algorithm is proposed. The features of the tag group are analyzed by the Gaussian algorithm, the region of interest of the dynamic tag is effectively framed, and the tag foreground is extracted; Secondly, the data set of tag groups are trained by the end-to-end YOLOv2 algorithm for secondary screening and recognition, and finally the specific locations of tags are framed to meet the effective identification of tag groups in different scenes. A considerable number of experiments illustrate that the fusion algorithm can significantly improve recognition accuracy. Combined with the reading distance, the research presented in this paper can more accurately optimize the three-dimensional structure of the tag group, improve the reading performance of the tag group, and avoid the interference and collision of tags in the communication channel. Compared with the previous template matching algorithm, the tag group recognition ability put forward in this paper is improved by at least 13.9%, and its reading performance is improved by at least 6.2% as shown in many experiments.
Źródło:
Metrology and Measurement Systems; 2022, 29, 1; 53-74
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and characterization of TiO2/ZSM-5 photocatalysts for degradation of rhodamine
Autorzy:
Liu, Rulai
Hu, Jiapeng
Rau, Juiye
Lin, Hao
He, Huan
Gao, Biao
Lai, Wenliang
Powiązania:
https://bibliotekanauki.pl/articles/2086909.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
photodegradation
TiO2
ZSM-5
kaolin clay
fotodegradacja
glinka kaolinowa
Opis:
ZSM-5 synthesized by the hydrothermal method from raw kaolin clay was used as support to prepare TiO2/ZSM-5 catalysts via the sol-gel method. All prepared samples were characterized by X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), ultraviolet-visible spectroscopy (UV-Vis), transmission electron microscopy (TEM), particle size analysis and surface area measurement. The photocatalytic performance of TiO2/ZSM-5 was investigated based on rhodamine B (RhB) removal under UV radiation (450-600 nm. The results showed that the kaolin clay was successfully transformed into ZSM-5. The BET surface area and pore size distribution of the synthesized ZSM-5 were 364 m2/g and 0.54 nm, respectively. SEM and TEM revealed that TiO2 nanoparticles were well distributed on the surface of ZSM-5. The composite TiO2/ZSM-5 catalyst showed 98.53% removal, which is higher than that of pure TiO2 (80.13%) due to adsorption and degradation of RhB (5.0 mg/dm3) under 60 min UV light irradiation at 1 g/dm3 photocatalyst loading. The synergistic effect of TiO22 and ZSM-5, including adsorption, conduction band electron (e-), and valence-band holes (h+), makes the composite superior to pure TiO2, showing its potential for the degradation of organic dye.
Źródło:
Environment Protection Engineering; 2022, 48, 2; 29--42
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Metal Oxides on the Thermal Decomposition Kinetics and Mechanisms of HAN/PVA Based Propellants
Autorzy:
Hu, Song-qi
Liu, Xue-li
Liu, Lin-Lin
Kang, Bo
Zhang, Yan
Powiązania:
https://bibliotekanauki.pl/articles/27787991.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
HAN/PVA-based propellant
metal oxides
catalytic behaviour
kinetic parameters
Opis:
The thermal decomposition processes of HAN/PVA-based propellants have been investigated using a simultaneous thermogravimetric analysis (TGA) – differential scanning calorimetry (DSC), coupled with Fourier-Transform Infrared Spectroscopy (FTIR) and Mass Spectrometry (MS) system. The activation energy (Ea), pre-exponential factor A and reaction mechanism function f(α) of the decomposition processes have been determined by non-isothermal and Malek methods. The results showed that the decomposition process of an HAN/PVA sample occurs mainly in the temperature range 202.2~220.1 °C, with a mass loss, heat release and Ea of about 84.8%, 1474.18 and 88.76 kJ·mol–1, respectively. Of the seven metal oxides studied as catalysts, Al2O3, V2O5 and Fe2O3 have significant catalytic effects on an HAN/PVA-based propellant, in lowering the decomposition temperature, with Ea changing from 88.8 to 83.7, 85.6 and 113.6 kJ·mol–1, respectively. The f(α) of both HAN/PVA and HAN/PVA/Al2O3 samples can be expressed as f(α) = (1 – α)2, whereas f(α) = α or f(α) = α/2 fit well for the HAN/PVA/V2O5 and HAN/PVA/Fe2O3 samples.
Źródło:
Central European Journal of Energetic Materials; 2021, 18, 3; 322-338
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sound Field Modelling and Noise Reduction for a Forklift Power Compartment Based on Perfectly Matched Layer and Acoustic Packaging Design
Autorzy:
Zhang, Enlai
Liu, Zhiqi
Zhang, Jingjing
Lin, Jiahe
Powiązania:
https://bibliotekanauki.pl/articles/1945640.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
forklift power compartment
sound field modelling
perfectly matched layer
acoustic packaging design
noise reduction
Opis:
The core goal of this paper is to put forward a feasible scheme of noise reduction for a target forklift on the basis of solving the problem of vibration and acoustic radiation from complex structures in infinite domain. Based on the previous report and vibration acceleration tests, the acoustic virtual wind tunnel model of forklift power compartment was established using finite element method and boundary element method, in which the perfectly matched layer was first applied to simulate the attenuation propagation of sound waves in air. In addition, according to the distribution characteristics of sound pressure field with different frequencies, the acoustic energy mainly radiated through the bottom and right side, and concentrated in the low frequency. Consequently, the acoustic packaging design for the whole forklift power compartment was presented, and a satisfying noise reduction effect was achieved.
Źródło:
Archives of Acoustics; 2021, 46, 3; 491-498
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A dynamic model for the heat transfer behavior of a cooling system
Autorzy:
Liu, Wen
Zhang, Chi
Hu, Xiao-Xiong
Cao, Jian-Bo
Liu, Li-Jiao
Ye, Xin-Y
Lin, Li
Qi, Xun-Ji
Powiązania:
https://bibliotekanauki.pl/articles/2050060.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
adsorption system
refrigerating system
desorption
simulation
Opis:
For purposes of studying the heat transfer behavior of various fluids in a refrigeration system, a dynamic model is established, obtained on the basis of analysis concerning the effects of adsorption velocity, adsorbent bed temperature, condensing temperature, and heat transfer fluids, as well as changes of external conditions. It is demonstrated that adsorption velocity increases sharply in the initial phase of adsorption process and gradually declines after reaching a peak value, whereas condensing temperature increases sharply in the initial phase of desorption process and decreases after reaching a peak value with the desorption quantity decreasing. Furthermore, the increase of heat source temperature and the decrease of cooling water temperature can advance the adsorption process. The present study therefore suggests some ways of improving the performance of such a refrigeration system by increasing heat source temperature, decreasing ambient air temperature, increasing return air temperature and decreasing cooling water temperature.
Źródło:
Control and Cybernetics; 2020, 49, 3; 315--332
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A numerical model for impacts of left-turn non-motorized vehicles on through lane capacity metrics
Autorzy:
He, Lieyun
Lin, Xinming
Liu, Qiang
Tao, Jason X,
Powiązania:
https://bibliotekanauki.pl/articles/1833648.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
traffic design
signalized intersection
permissive phase
traffic lane capacity
regression analysis
projektowanie ruchu
skrzyżowanie sygnalizowane
faza permisywna
przepustowość pasów ruchu
analiza regresji
Opis:
There is a conflict between through motor vehicles and the left-turn non-motorized vehicles, and the capacity of straight-line motor vehicles decreases. This study analyzes the impacts of left-turn non-motorized vehicles on the capacity of through motor vehicle lanes. A correction coefficient model for calculating the reduced capacity of through motor vehicle lanes has been developed based on analysis of the conflicting points at an intersection and the negative exponential function of traffic flow distribution. With consideration of intersection geometric design, channelization, and traffic characteristics, the cor-rection coefficient model was further enhanced by regression to capture the impacts of left-turn non-motorized vehicles from the same and the opposite directions. A simulation with VISSIM is used to validate the developed model. It shows that the calculated capacity from the correction coefficient model is close to the simulation results. The experiment indicates that the derived model is highly accurate in calculating the capacity of through motor vehicle lanes and has potential application for situations of mixed traffic in China. The study shows that the capacity of a through traffic lane at the permitted phase decreases with the increase of left-turning non-motorized vehicles, and the impact of left-turning non-motorized vehicles from the same direction is more significant. The results show that the traffic capacity of straight-line motor vehicle decreases with the increase of the left-turn non-motorized vehicles flow rate and the influence of the left-turn non-motor vehicle is more obvious. It is suggested that in practice, the correction coefficient of non-motor vehicle on the left turn should be 0.88, and the correction coefficient on the left turn should be 0.95, respectively. The study recommends coefficient values for both non-motorized vehicles from the same and opposite directions for use in real applications.
Źródło:
Archives of Transport; 2020, 55, 3; 7-16
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of the degree of polymerization of nonylphenol polyoxyethylene ether on the dewatering of low-rank coal
Autorzy:
Li, Lin
He, Meng
Liu, Mingpu
Lin, Mengyu
Hu, Shanpei
Yu, Hao
Wang, Qingbiao
You, Xiaofang
Powiązania:
https://bibliotekanauki.pl/articles/1449205.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
low-rank coal
NPEO
dewatering
adsorption
long-flame coal
Opis:
In this study, we investigated the effect of the hydrophilic ethylene oxide chain lengths (i.e., degree of polymerization) of nonylphenol polyoxyethylene ether (NPEO-x, x = 8, 10, and 12) on the dewatering of low-rank coal slime through dewatering and adsorption experiments and X-ray photoelectron spectroscopy (XPS) measurements. The dewatering experiments showed that the adsorption of NPEO changed the water content of the low-rank coal slime: NPEO-8 achieved the best effect, followed, in decreasing order, by NPEO-10 and NPEO-12. Adsorption experiments revealed that the adsorption isotherms of NPEO-x on the low-rank coal surface conform with the Langmuir model, and its adsorption kinetics follow the pseudo-second-order kinetic equation. Furthermore, the adsorption is a spontaneous process and controlled by both intraparticle diffusion and liquid film diffusion. The XPS results showed that the adsorption of NPEO-x decreased the content of oxygencontaining groups and, thus, improved the hydrophobicity of the low-rank coal surface. Further, the use of NPEO-x with a low degree of polymerization (x = 8) improves the hydrophobicity of the coal surface and decreases the water content of low-rank coal slime.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 4; 723-736
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Speech Enhancement Based on Discrete Wavelet Packet Transform and Itakura-Saito Nonnegative Matrix Factorisation
Autorzy:
Liu, Houguang
Wang, Wenbo
Xue, Lin
Yang, Jianhua
Wang, Zhihua
Hua, Chunli
Powiązania:
https://bibliotekanauki.pl/articles/1448505.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
speech enhancement
discrete wavelet packet transform
nonnegative matrix factorisation
Itakura-Saito divergence
Opis:
Nonnegative matrix factorization (NMF) is one of the most popular machine learning tools for speech enhancement (SE). However, there are two problems reducing the performance of the traditional NMF-based SE algorithms. One is related to the overlap-and-add operation used in the short time Fourier transform (STFT) based signal reconstruction, and the other is the Euclidean distance used commonly as an objective function; these methods can cause distortion in the SE process. In order to get over these shortcomings, we propose a novel SE joint framework which combines the discrete wavelet packet transform (DWPT) and the Itakura-Saito nonnegative matrix factorisation (ISNMF). In this approach, the speech signal was first split into a series of subband signals using the DWPT. Then, the ISNMF was used to enhance the speech for each subband signal. Finally, the inverse DWPT (IDWT) was utilised to reconstruct these enhanced speech subband signals. The experimental results show that the proposed joint framework effectively enhances the performance of speech enhancement and performs better in the unseen noise case compared to the traditional NMF methods.
Źródło:
Archives of Acoustics; 2020, 45, 4; 565-572
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The List Edge Coloring and List Total Coloring of Planar Graphs with Maximum Degree at Least 7
Autorzy:
Sun, Lin
Wu, Jianliang
Wang, Bing
Liu, Bin
Powiązania:
https://bibliotekanauki.pl/articles/31348158.pdf
Data publikacji:
2020-11-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
planar graph
list edge coloring
list total coloring
Opis:
A graph $G$ is edge $k$-choosable (respectively, total $k$-choosable) if, whenever we are given a list $L(x)$ of colors with $|L(x)| = k$ for each $x ∈ E(G) (x ∈ E(G) ∪ V (G))$, we can choose a color from $L(x)$ for each element $x$ such that no two adjacent (or incident) elements receive the same color. The list edge chromatic index $χ_l^′(G)$ (respectively, the list total chromatic number $χ_l^{′′}(G))$ of $G$ is the smallest integer $k$ such that $G$ is edge (respectively, total) $k$-choosable. In this paper, we focus on a planar graph $G$, with maximum degree $Δ (G) ≥ 7$ and with some structural restrictions, satisfies $χ_l^′(G) = Δ (G)$ and $χ_l^{′′}(G) = Δ (G) + 1$.
Źródło:
Discussiones Mathematicae Graph Theory; 2020, 40, 4; 1005-1024
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultra-short-term wind power prediction based on copula function and bivariate EMD decomposition algorithm
Autorzy:
Liu, Haiqing
Lin, Weijian
Li, Yuancheng
Powiązania:
https://bibliotekanauki.pl/articles/140702.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
bivariate EMD decomposition
copula function
GRU network
meteorological factor
ultra-short-term wind power prediction
Opis:
Against the background of increasing installed capacity of wind power in the power generation system, high-precision ultra-short-term wind power prediction is significant for safe and reliable operation of the power generation system. We present a method for ultra-short-term wind power prediction based on a copula function, bivariate empirical mode decomposition (BEMD) algorithm and gated recurrent unit (GRU) neural network. First we use the copula function to analyze the nonlinear correlation between wind power and external factors to extract the key factors influencing wind power generation. Then the joint data composed of the key factors and wind power are decomposed into a series of stationary subsequence data by a BEMD algorithm which can decompose the bivariate data jointly. Finally, the prediction model based on a GRU network uses the decomposed data as the input to predict the power output in the next four hours. The experimental results show that the proposed method can effectively improve the accuracy of ultra-short-term wind power prediction.
Źródło:
Archives of Electrical Engineering; 2020, 69, 2; 271-286
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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