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Wyszukujesz frazę "Zhang, Zhao" wg kryterium: Autor


Tytuł:
Evaluation of medical service quality based on a novel multi-criteria decision-making method with unknown weighted information
Autorzy:
Zhao, Butian
Zhang, Runtong
Xing, Yuping
Powiązania:
https://bibliotekanauki.pl/articles/1845522.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
interval-valued q-rung dual hesitant fuzzy set
Maclaurin symmetric mean
operator
multi-criteria decision-making
aggregation operators
Opis:
In modern society, people concern more about the evaluation of medical service quality. Evaluation of medical service quality is helpful for medical service providers to supervise and improve their service quality. Also, it will help the public to understand the situation of different medical providers. As a multi-criteria decision-making (MCDM) problem, evaluation of medical service quality can be effectively solved by aggregation operators in interval-valued q-rung dual hesitant fuzzy (IVq-RDHF) environment. Thus, this paper proposes interval-valued q-rung dual hesitant Maclaurin symmetric mean (IVq-RDHFMSM) operator and interval-valued q-rung dual hesitant weighted Maclaurin symmetric mean (IVq-RDHFWMSM) operator. Based on the proposed IVq-RDHFWMSM operator, this paper builds a novel approach to solve the evaluation problem of medical service quality including a criteria framework for the evaluation of medical service quality and a novel MCDM method. What’s more, aiming at eliminating the discordance between decision information and weight vector of criteria determined by decisionmakers (DMs), this paper proposes the concept of cross-entropy and knowledge measure in IVq-RDHF environment to extract weight vector from DMs’ decision information. Finally, this paper presents a numerical example of the evaluation of medical service for hospitals to illustrate the availability of the novel method and compares our method with other MCDM methods to demonstrate the superiority of our method. According to the comparison result, our method has more advantages than other methods.
Źródło:
Archives of Control Sciences; 2021, 31, 3; 645-685
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of medical service quality based on a novel multi-criteria decision-making method with unknown weighted information
Autorzy:
Zhao, Butian
Zhang, Runtong
Xing, Yuping
Powiązania:
https://bibliotekanauki.pl/articles/1845505.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
interval-valued q-rung dual hesitant fuzzy set
Maclaurin symmetric mean operator
multi-criteria decision-making
aggregation operators
Opis:
In modern society, people concern more about the evaluation of medical service quality. Evaluation of medical service quality is helpful for medical service providers to supervise and improve their service quality. Also, it will help the public to understand the situation of different medical providers. As a multi-criteria decision-making (MCDM) problem, evaluation of medical service quality can be effectively solved by aggregation operators in interval-valued q-rung dual hesitant fuzzy (IVq-RDHF) environment. Thus, this paper proposes interval-valued q-rung dual hesitant Maclaurin symmetric mean (IVq-RDHFMSM) operator and interval-valued q-rung dual hesitant weighted Maclaurin symmetric mean (IVq-RDHFWMSM) operator. Based on the proposed IVq-RDHFWMSM operator, this paper builds a novel approach to solve the evaluation problem of medical service quality including a criteria framework for the evaluation of medical service quality and a novel MCDM method. What’s more, aiming at eliminating the discordance between decision information and weight vector of criteria determined by decisionmakers (DMs), this paper proposes the concept of cross-entropy and knowledge measure in IVq-RDHF environment to extract weight vector from DMs’ decision information. Finally, this paper presents a numerical example of the evaluation of medical service for hospitals to illustrate the availability of the novel method and compares our method with other MCDM methods to demonstrate the superiority of our method. According to the comparison result, our method has more advantages than other methods.
Źródło:
Archives of Control Sciences; 2021, 31, 3; 645-685
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved classification robust Kalman filtering method for precise point positioning
Autorzy:
Zhang, Qieqie
Zhao, Long
Zhou, Jianhua
Powiązania:
https://bibliotekanauki.pl/articles/220468.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Kalman filter
classification robust
equivalent weight function
precise point positioning
Opis:
The accuracy and reliability of Kalman filter are easily affected by the gross errors in observations. Although robust Kalman filter based on equivalent weight function models can reduce the impact of gross errors on filtering results, the conventional equivalent weight function models are more suitable for the observations with the same noise level. For Precise Point Positioning (PPP) with multiple types of observations that have different measuring accuracy and noise levels, the filtering results obtained with conventional robust equivalent weight function models are not the best ones. For this problem, a classification robust equivalent weight function model based on the t-inspection statistics is proposed, which has better performance than the conventional equivalent weight function models in the case of no more than one gross error in a certain type of observations. However, in the case of multiple gross errors in a certain type of observations, the performance of the conventional robust Kalman filter based on the two kinds of equivalent weight function models are barely satisfactory due to the interaction between gross errors. To address this problem, an improved classification robust Kalman filtering method is further proposed in this paper. To verify and evaluate the performance of the proposed method, simulation tests were carried out based on the GPS/BDS data and their results were compared with those obtained with the conventional robust Kalman filtering method. The results show that the improved classification robust Kalman filtering method can effectively reduce the impact of multiple gross errors on the positioning results and significantly improve the positioning accuracy and reliability of PPP.
Źródło:
Metrology and Measurement Systems; 2019, 26, 2; 267-281
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Grid-side current harmonic suppression based on Butterworth filter and quasi-proportional resonance controller
Autorzy:
Zhao, Feng
Zhang, Jianing
Chen, Xiaoqiang
Wang, Ying
Powiązania:
https://bibliotekanauki.pl/articles/2172801.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Butterworth filter
current harmonic suppression
high-speed electric multiple units
quasi-PR controller
traction drive system
Opis:
In order to meet the lightweight requirements of high-speed trains, the inductancecapacitance (LC) resonance circuits are cancelled in the traction drive system of some high-speed electric multiple units (EMUs) in China, which will lead to large low-order current harmonics on the grid side in the traction drive system of EMUs, seriously affecting the power quality. Therefore, the low-order harmonic current of the traction drive system of an EMU is studied in this paper. Firstly, the working principle of a four-quadrant pulse rectifier in a traction drive system is analyzed, and then the generation mechanism of loworder current harmonics on the grid side is studied deeply. Secondly, the voltage outer loop and current inner loop control of a four-quadrant pulse rectifier are optimized respectively. In the voltage outer loop control, a Butterworth filter is designed to suppress the beat frequency voltage of the DC side voltage, so as to indirectly suppress the low-order current harmonics. In the current inner loop, a quasi-proportional resonance (PR) controller with harmonic compensation is used to suppress low-order current harmonics, and a novel loworder current harmonics suppression strategy based on the Butterworth filter and quasi-PR controller is proposed. Finally, the results of the simulated validation of the proposed control strategy show that compared with the existing method of the notch filter ₊ PR controller, the proposed optimal control strategy has a better effect on low-order current harmonic suppression, and improves the dynamic performance of the control system, further showing the correctness and effectiveness of the optimal control strategy.
Źródło:
Archives of Electrical Engineering; 2022, 71, 4; 909--929
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ferrite Decarburization of High Silicon Spring Steel in Three Temperature Ranges
Autorzy:
Zhao, F.
Zhang, C. L.
Liu, Y. Z.
Powiązania:
https://bibliotekanauki.pl/articles/350822.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
surface decarburization
steel
oxidation
carbon diffusion
Opis:
Surface decarburization of high silicon spring steel in ambient air was studied. The experimental results confirmed the decarburized mechanism under AC1 temperature, in the temperature range of AC1-AC3 and AC3-G. Under AC1 temperature, pearlite spheroidization and surface decarburization are carried out simultaneously and pearlite spheroidization is reinforced. Considering the oxidation loss depth, the “true ferrite decarburized depth” at 850 °C (AC3-G) is still smaller than that at 760°C (AC1-AC3). That is because an “incubation period” must pass away before ferrite decarburization occurs in the temperature range of AC3-G, and the ferrite decarburized rate is limited to being equal to the partial decarburized rate.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 3; 1715-1722
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Relationship Between Bake Hardening, Snoek-Köster and Dislocation-Enhanced Snoek Peaks in Coarse Grained Low Carbon Steel
Autorzy:
Lin, W.
Zhao, S.
Zhang, H.
Jin, X.
Powiązania:
https://bibliotekanauki.pl/articles/353663.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
low carbon steel
ultra-low carbon bake-hardening (ULC-BH) steel
bake hardening (BH)
Snoek peak
dislocation-enhanced Snoek peak
Snoek-Köster peak
internal friction
Opis:
In the present work, specimens prepared from coarse grained low carbon steel with different prestrains were baked and then, their bake hardening (BH) property and internal friction were determined. TEM was used to characterize the dislocation structure in BH treated samples. The measurements of internal friction in prestrained samples and baked samples were carried out using a multifunctional internal friction apparatus. The results indicate that, in coarse grained low carbon steel, the bake hardening properties (BH values) were negative, which were increased by increasing the prestrain from 2 to 5%, and then were decreased by increasing the prestrain from 5 to 10%. In the specimen with prestrain 5%, the BH value reached the maximum value and the height of Snoek-Köster peak was observed to be the maximum alike. With increasing the prestrain, both of the BH value and Snoek-Köster peak heights are similarly varied. It is concluded that Snoek-Köster and dislocation-enhanced Snoek peaks, caused by the interactions between interstitial solute carbon atoms and dislocations, can be used in further development of the bake hardening steels.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 3; 1723-1732
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Specific emitter identification using geometric features of frequency drift curve
Autorzy:
Zhao, Y.
Wui, L.
Zhang, J.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/200575.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
specific emitter identification
geometric features
frequency drift
adaptive fractional spectrogram
support vector machine
emiter
cechy geometryczne
dryf częstotliwości
spektrogram
Opis:
Specific emitter identification (SEI) is a technique for recognizing different emitters of the same type which have the same modulation parameters. Using only the classic modulation parameters for recognition, one cannot distinguish different emitters of a same type. To solve the problem, new features urgently need to be developed for recognition. This paper focuses on the common phenomenon of frequency drift, defines geometric features of frequency drift curve and, finally, proposes a practical algorithm of specific emitter identification using the geometric features. The proposed algorithm consists of three processes: instantaneous frequency estimation based on the adaptive fractional spectrogram, feature extraction of frequency drift curve based on geometric methods for describing a curve and recognition process based on support vector machine. Simulation results show that the identification rate is generally more than 98% above –5 dB of signal to noise ratio (SNR), and real data experiment verifies the practical performance of the proposed algorithm.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2018, 66, 1; 99-108
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructures and Microwave-Absorbing Properties of ZnO Smoke from Zinc Leach Residue Treated by Carbothermal Reduction
Autorzy:
Ma, Zhiwei
Wang, Sheng
Du, Xueyan
Zhang, Ji
Zhao, Ruifeng
Zhang, Shengquan
Powiązania:
https://bibliotekanauki.pl/articles/2049146.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
zinc leach residue
carbothermal reduction
ZnO smoke
microwave-absorbing properties
Opis:
Much zinc residue is produced during the traditional processes involved in zinc hydrometallurgy in the leaching stage: its composition is complex and valuable metals are difficult to recover therefrom. If not handled properly, it can lead to a waste of resources and environmental pollution. To solve this problem, zinc leach residue specimens were treated using the carbothermal reduction method (CTR) that is easy to operate and has a high energy utilisation rate. The methods, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM) were used for analytical characterisation. Based on this, this research investigated a structure-function relationship between microstructures and microwave-absorbing properties of ZnO smoke from CTR-treated zinc leach residue. The results demonstrate that microstructures and macro-properties of ZnO smoke obtained at different temperatures differ greatly. Under conditions including a calcination temperature of 1250°C, holding time of 60 min, and addition of 50% and 10% of powdered coal and CaO separately, the ZnO content in the obtained smoke is 99.14%, with regular micron-sized ZnO particles therein. For these particles, the minimum reflection loss (RLmin) reached –25.56 dB at a frequency of 15.84 GHz with a matching thickness of 5 mm. Moreover, frequency bandwidth corresponding to RL < –10 dB can reach 2.0 GHz. ZnO smoke obtained using this method is found to have excellent microwave-absorbing performance, which provides a new idea for high-value applications of zinc-rich residue.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 4; 1163--1170
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect Of Low-Temperature Annealing On The Properties Of Ni-P Amorphous Alloys Deposited Via Electroless Plating
Wpływ oceny mikrostruktury na odporność korozyjną wyżarzonego stopu amorficznego Ni-P
Autorzy:
Zhao, G.
Zou, Y.
Zhang, H.
Zou, Z.
Powiązania:
https://bibliotekanauki.pl/articles/351971.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Ni-P amorphous
local atomic structure
corrosion resistance
microhardness
stopy amorficzne Ni-P
lokalna struktura atomowa
odporność na korozję
mikrotwardość
Opis:
Amorphous Ni-P alloys were prepared via electroless plating and annealing at 200°C at different times to obtain different microstructures. The effects of low-temperature annealing on the properties of amorphous Ni-P alloys were studied. The local atomic structure of the annealed amorphous Ni-P alloys was analyzed by calculating the atomic pair distribution function from their X-ray diffraction patterns. The results indicate that the properties of the annealed amorphous Ni-P alloys are closely related to the order atomic cluster size. However, these annealed Ni-P alloys maintained their amorphous structure at different annealing times. The variation in microhardness is in agreement with the change in cluster size. By contrast, the corrosion resistance of the annealed alloys in 3.5 wt% NaCl solution increases with the decrease in order cluster size.
Amorficzne stopy Ni-P otrzymane metodą powlekania bezprądowego wyżarzano w temperaturze 200°C w różnych czasach, w celu otrzymania zróżnicowanej mikrostruktur. Badano wpływ mikrostruktury wyżarzanych stopów amorficznych Ni-P na ich odporność korozyjną w roztworze 3,5% wag. NaCl. Wyniki wskazują, że wielkość klastra w wyżarzanych stopach amorficznych Ni-P najpierw zmniejszyła się, a następnie zwiększyła wraz z czasem wyżarzania. Odporność badanych stopów na korozję jest ściśle związana z wielkością klastra, mimo, że stopy te po wyżarzaniu w różnych czasach zachowują strukturę amorficzną. Odporność wyżarzanych stopów amorficznych Ni-P w roztworze 3,5% wag. NaCl zwiększa się wraz ze zmniejszeniem się klastra.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2A; 865-869
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecular cloning, expression, purification and osteoblasts proliferation activity of sika deer thymosin beta10
Autorzy:
Zhao, D.
Zhao, Y.
Zhang, H.
Xu, Z.
Liu, M.
Wang, J.
Bai, X.
Powiązania:
https://bibliotekanauki.pl/articles/2087874.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
affinity chromatography
cell proliferation
prokaryotic expression
sika deer
thymosin 10
Źródło:
Polish Journal of Veterinary Sciences; 2017, 4; 751-758
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fatigue Behavior and Mechanism of FV520B-I Owing to the Effect of Loading Frequency on the Fatigue Property in HCF and VHCF Regime
Autorzy:
Wang, J.
Zhang, Y.
Shi, B.
Zhao, Q.
Sun, Q.
Zhang, Z.
Lu, H.
Powiązania:
https://bibliotekanauki.pl/articles/353784.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrahigh loading frequency
FV520B-I
fatigue strength
fatigue conversion model
Opis:
Fatigue property of FV520B-I is affected by the ultrahigh loading frequency significantly, and the ultrasonic fatigue experimental data can’t be employed directly to analyze the fatigue failure in the actual remanufacturing engineering. However few theories about the effect of loading frequency on the fatigue property of FV520B-I has ever been proposed. In this paper, both ultrasonic experiment and conventional experiment are conducted out to obtain the fatigue data. The effect of loading frequency on the fatigue data distribution is discussed firstly, its fatigue limit declines with the increase of the loading frequency. Then the fracture surface observations are captured, the fatigue property and fatigue behavior mechanism of FV520B-I is examined by analyzing the fracture surface features, crack initiation and failure observations. A new material frequency correction factor is proposed and introduced to eliminate the influence of the loading frequency on the FV520B-I fatigue property. FV520B-I empirical fatigue life conversion model and fatigue strength conversion model are established with comprehensive use of a fitting algorithm based on the combination of experimental data and classic formula. A clear understand of the effect of loading frequency on the fatigue property of FV520B-I is novel and has an important significance in guaranteeing the accuracy of the actual fatigue analysis of FV520B-I in the remanufacturing engineering.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 1; 347-357
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Speech Enhancement Based on the Multi-Scales and Multi-Thresholds of the Auditory Perception Wavelet Transform
Autorzy:
Tao, Z.
Zhao, H. M.
Zhang, X-J.
Wu, D.
Powiązania:
https://bibliotekanauki.pl/articles/177021.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
speech enhancement
low SNR
auditory perception wavelet transform
unvoiced enhancement
masking effect
Opis:
This paper proposes a speech enhancement method using the multi-scales and multi-thresholds of the auditory perception wavelet transform, which is suitable for a low SNR (signal to noise ratio) environment. This method achieves the goal of noise reduction according to the threshold processing of the human ear’s auditory masking effect on the auditory perception wavelet transform parameters of a speech signal. At the same time, in order to prevent high frequency loss during the process of noise suppression, we first make a voicing decision based on the speech signals. Afterwards, we process the unvoiced sound segment and the voiced sound segment according to the different thresholds and different judgments. Lastly, we perform objective and subjective tests on the enhanced speech. The results show that, compared to other spectral subtractions, our method keeps the components of unvoiced sound intact, while it suppresses the residual noise and the background noise. Thus, the enhanced speech has better clarity and intelligibility.
Źródło:
Archives of Acoustics; 2011, 36, 3; 519-532
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Applied research of U-shape ventilation network in underground mine
Badania stosowane w sieci wentylacyjnej w kształcie „U” w kopalni podziemnej
Autorzy:
Zhang, H.
Pera, L. S.
Carla, V. S.
Zhao, Y.
Powiązania:
https://bibliotekanauki.pl/articles/219698.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
eksperyment symulacyjny
wentylacja kopalni
prędkość przepływu
podobieństwo dynamiczne
simulation experiment
mine ventilation
wind velocity
dynamic similarity
Opis:
For the purpose of fully and systematically observe, research and optimize the U-sharp ventilation system in Vilafruns mine, a simulation model based on the principles of geometric, kinematic and dynamic similarity is established in the simulation laboratory. By simulating a U-shape ventilation network, t he air volume distribution and wind velocity in different sections of the model were measured and compared with practical data obtained in Vilafruns mine. Results show that the lowest wind velocity in the model is higher than 0.42 m/s, thus it is in a turbulent f low state, which satisfies the kinematical and dynamic similarity principles. T he characteristic of air volume distribution and wind velocity in Vilafruns mine are basically simulated by the experimental model through the obtained data and figures, which reflects the establishment of the model is correct and successful, and the experimental data is accurate and reliable. Moreover, this model provides useful references for the selection of mine ventilation types and for the optimization of the existing ventilation network.
W celu prowadzenia pełnej i systematycznej obserwacji, badań oraz optymalizacji sieci wentylacyjnej w kopalni Vilafruns, opracowano model do symulacji laboratoryjnych w oparciu o zasady podobieństwa geometrycznego, kinematycznego oraz dynamicznego. W ramach symulacji działania sieci wentylacyjnej w kształcie litery U, dokonano pomiarów rozkładu objętości powietrza oraz prędkości ruchu powietrza w różnych sekcjach modelu. Dane te porównano następnie z danymi rzeczywistymi uzyskanymi w kopalni Vilafruns. Wyniki pokazują, że najniższa prędkość przepływu powietrza w modelu przewyższa 0.42 m/s, mamy więc do czynienia z przepływem turbulentnym, w ten sposób spełnione są warunki podobieństwa kinematycznego i dynamicznego. Charakterystyka rozkładu objętości powietrza i prędkości przepływu w kopalni Vilafruns zasadniczo otrzymana została na podstawie modelu eksperymentalnego z wykorzystaniem uzyskanych wyników. Oznacza to, że zasadniczo model jest poprawny i skuteczny a dane eksperymentalne są dokładne i wiarygodne. Ponadto, model dostarcza nam cennych danych wyjściowych niezbędnych przy wyborze systemu wentylacji, a także przy optymalizacji istniejącej sieci wentylacyjnej.
Źródło:
Archives of Mining Sciences; 2014, 59, 2; 381-394
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Defect recognition of buried pipeline based on approximate entropy and variational mode decomposition
Autorzy:
Ju, Haiyang
Wang, Xinhua
Zhang, Tao
Zhao, Yizhen
Ullah, Zia
Powiązania:
https://bibliotekanauki.pl/articles/221572.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Buried Pipeline
Defect Recognition
Geomagnetic Anomaly Detection
Variational Mode Decomposition
Approximate Entropy
Opis:
The study aimed to examine the use of Geomagnetic Anomaly Detection (GAD) to locate the buried ferromagnetic pipeline defects without exposing them. However, the accuracy of GAD is limited by the background noise. In the present work, we propose an approximate entropy noise suppression (AENS) method based on Variational Mode Decomposition (VMD) for detection of pipeline defects. The proposed method is capable of reconstructing the magnetic field signals and extracting weak anomaly signals that are submerged in the background noise, which was employed to construct an effective detector of anomalous signals. The internal parameters of VMD were optimized by the Scale–Space algorithm, and their anti-noise performance was compared. The results show that the proposed method can remove the background noise in high-noise background geomagnetic field environments. Experiments were carried out in our laboratory and evaluation results of inspection data were analysed; the feasibility of GAD is validated when used in the application to detection of buried pipeline defects.
Źródło:
Metrology and Measurement Systems; 2019, 26, 4; 739-755
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on electric vehicle charging load prediction and charging mode optimization
Autorzy:
Zhang, Zhiyan
Shi, Hang
Zhu, Ruihong
Zhao, Hongfei
Zhu, Yingjie
Powiązania:
https://bibliotekanauki.pl/articles/1841299.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
electric vehicles
Monte Carlo
wavelet neural network
charging load
pojazdy elektryczne
sieć neuronowa falkowa
Opis:
To reduce the influence of the disorderly charging of electric vehicles (EVs) on the grid load, the EV charging load and charging mode are studied in this paper. First, the distribution of EV charging capacity and state of charge (SOC) feature quantity are analyzed, and their probability density function is solved. It is verified that both EV charging capacity and SOC obey the skew-normal distribution. Second, considering the space-time distribution characteristics of the EV charging load, a method for charging load prediction based on a wavelet neural network is proposed, and compared with the traditional BP neural network, the prediction results show that the error of the wavelet neural network is smaller, and the effectiveness of the wavelet neural network prediction is verified. The optimization objective function with the lowest user costs is established, and the constraint conditions are determined, so the orderly charging behavior is simulated by the Monte Carlo method. Finally, the influence of charging mode optimization on power grid operation is analyzed, and the result shows that the effectiveness of the charging optimization model is verified.
Źródło:
Archives of Electrical Engineering; 2021, 70, 2; 399-414
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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