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Wyszukujesz frazę "Zhang, Zhao" wg kryterium: Autor


Tytuł:
Three-dimensional path-following control of an autonomous underwater vehicle based on deep reinforcement learning
Autorzy:
Liang, Zhenyu
Qu, Xingru
Zhang, Zhao
Chen, Cong
Powiązania:
https://bibliotekanauki.pl/articles/32898215.pdf
Data publikacji:
2022
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
autonomous underwater vehicle (AUV)
three-dimensional path following
deep reinforcement learning-based control
lineof-sight guidance
controller chattering
Opis:
In this article, a deep reinforcement learning based three-dimensional path following control approach is proposed for an underactuated autonomous underwater vehicle (AUV). To be specific, kinematic control laws are employed by using the three-dimensional line-of-sight guidance and dynamic control laws are employed by using the twin delayed deep deterministic policy gradient algorithm (TD3), contributing to the surge velocity, pitch angle and heading angle control of an underactuated AUV. In order to solve the chattering of controllers, the action filter and the punishment function are built respectively, which can make control signals stable. Simulations are carried out to evaluate the performance of the proposed control approach. And results show that the AUV can complete the control mission successfully.
Źródło:
Polish Maritime Research; 2022, 4; 36-44
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A multi-model based adaptive reconfiguration control scheme for an electro-hydraulic position servo system
Autorzy:
Zhang, Zhao
Yang, Zhong
Liu, Shuchang
Chen, Shuang
Zhang, Xiaokai
Powiązania:
https://bibliotekanauki.pl/articles/2124780.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
fault tolerant control
electro hydraulic position
servo system
multiple model
adaptive control
reconfiguration control
sterowanie tolerujące uszkodzenia
serwomechanizm
sterowanie adaptacyjne
Opis:
Reliability and safety of an electro-hydraulic position servo system (EHPSS) can be greatly reduced for potential sensor and actuator faults. This paper proposes a novel reconfiguration control (RC) scheme that combines multi-model and adaptive control to compensate for the adverse effects. Such a design includes several fixed models, one adaptive model, and one reinitialized adaptive model. Each of the models has its own independent controller that is based on a complete parametrization of the corresponding fault. A proper switching mechanism is set up to select the most appropriate controller to control the current plant. The system output can track the reference model asymptotically using the proposed method. Simulation results validate robustness and effectiveness of the proposed scheme. The main contribution is a reconfiguration control method that can handle component faults and maintain the acceptable performance of the EHPSS.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2022, 32, 2; 185--196
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interior Perforation Flow Field Study of Partially Cut 7-Perforated Stick Propellants
Autorzy:
Zhao, Xiaoliang
Zhang, Xiaobing
Powiązania:
https://bibliotekanauki.pl/articles/358092.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
partially cut
7-perforation stick propellants
internal perforation flow field
pressure difference
gas velocity
Opis:
Partially cut 7-perforated propellants are used in gun charges because of their good flame spreading, high progressivity and loading density. To investigate the complex flow field in a partially cut multi-perforation stick propellant, a steady three-dimensional model for compressible viscid internal perforation and the vent gas region flow field was established and simulated by ANSYS Fluent. The results illustrate that the cut vent can decrease the internal perforation pressure and end face gas velocity. Moreover, the mass that escaped through the vent to the outside was 85.3% of the whole internal burning propellant gas. When the width of the cut slot was larger than half the diameter, the internal pressure decreased weakly and the progressive intensity decreased slightly as the cut slot was increased. As the same side intervals were increased or the perforation diameters were decreased, the end face gas velocity and the internal and external perforation pressure differences increased, and the propellant combustion area progressive intensity increased. As the web thickness increased, the internal pressure increased, and gas velocity exhibited an upward tendency and reached peak values when 2e1 = 0.84 mm, whilst the progressive intensity increased slightly.
Źródło:
Central European Journal of Energetic Materials; 2019, 16, 4; 564-582
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An integrated approach to estimate storage reliability with masked data from series system
Autorzy:
Zhang, Yongjin
Zhao, Ming
Powiązania:
https://bibliotekanauki.pl/articles/27322965.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
storage reliability
masked data
EM-LS algorithm
series system
LS method
Opis:
Storage reliability is of importance for the products that largely stay in storage in their total life-cycle such as warning systems for harmful radiation detection, and many kinds of defense systems, etc. Usually, the field-testing data can be available, but the failure causes for a series system cannot be always known because of the masked information. In this paper, the storage reliability model with possibly initial failures is studied on the statistical analysis method when the masked data are considered. To optimize the use of the masked survival data from storage systems, a technique based on the least squares (LS) method with an EM-like algorithm, is proposed for the series system. The parametric estimation procedure based on the LS method is developed by applying the algorithm to update the testing data, and then the LS estimation for the initial reliability and failure rate of the components constituting the series system are investigated. In the case of exponentially distributed storage lifetime, a numerical example is provided to illustrate the method and procedure. The results should be useful for accurately evaluating the production reliability, identifying the production quality, and planning a storage environment.
Źródło:
Eksploatacja i Niezawodność; 2023, 25, 4; art. no. 172922
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Compound fault detection in gearbox based on time synchronous resample and adaptive variational mode decomposition
Wykrywanie złożonych błędów przekładni na podstawie synchronicznego próbkowania wtórnego oraz adaptacyjnej metody wariacyjnej dekompozycji modalnej
Autorzy:
Zhang, Xin
Zhao, Jianmin
Powiązania:
https://bibliotekanauki.pl/articles/301230.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
compound fault
gearbox
time synchronous resample
adaptive variational mode decomposition
błąd złożony
przekładnia
synchroniczne próbkowanie wtórne
adaptacyjna metoda wariacyjnej dekompozycji modalnej
Opis:
Compound fault detection of gearboxes is an ambitious matter considering its interconnection and complication. An innovative means for compound fault detection based on time synchronous resample (TSR) and adaptive variational mode decomposition (AVMD) is put forward in this work. TSR used in the method can enhance fault signals of synchronous shaft gears by eliminating signal components independent of synchronous shaft. Therefore, the TSR is used to separate the synchronous shaft signal corresponding to the gear fault from the raw compound fault signal. Then a series of mode components are obtained by decomposing the synchronous shaft signals of all faults by AVMD. The variational mode decomposition (VMD) can overcome the mode aliasing problem of empirical mode decomposition (EMD), but the decomposition effect of VMD is affected by its parameter setting. Thus, the paper proposes an AVMD algorithm based on whale optimization algorithm (WOA). In the AVMD, the WOA is used to optimizes the parameters of the VMD. After AVMD decomposition, the correlated kurtosis of the mode components obtained by AVMD decomposition is calculated. Then the mode components with the maximum correlated kurtosis are selected to carry out envelope analysis. Finally, the compound fault feature can be found from the envelope spectrum to get the diagnosis results. In order to test the validity of the proposed method, a compound fault experiment is implemented in a gearbox. Through the analysis of the experimental data, it is proved that the method shows a good performance in the compound fault detection of gearbox.
Wykrywanie złożonych błędów przekładni stanowi trudne zagadnienie ze względu na ich skomplikowany charakter i powiązania wewnętrzne. W pracy zaproponowano nowatorską metodę wykrywania błędów złożonych opartą na synchronicznym próbkowaniu wtórnym (TSR) oraz adaptacyjnej metodzie wariacyjnej dekompozycji modalnej (AVMD). TSR pozwala wzmacniać sygnały błędów występujących w synchronicznych przekładniach walcowych, dzięki eliminacji składowych sygnału niezwiązanych z działaniem wału synchronicznego. Dlatego też w przedstawionych badaniach, TSR wykorzystano do wyodrębnienia sygnału wału synchronicznego odpowiadającego błędowi przekładni, z surowego sygnału błędu złożonego. Następnie wszystkie sygnały błędu wału synchronicznego poddano dekompozycji za pomocą AVMD, dzięki czemu otrzymano szereg składowych modalnych. Wariacyjna dekompozycja modalna (VMD) pozwala uniknąć problemu aliasingu, który występuje w przypadku empirycznej dekompozycji modalnej (EMD), przy czym efekt dekompozycji zależy od ustawień parametrów. Dlatego w artykule zaproponowano adaptacyjny algorytm VMD oparty na algorytmie optymalizacji wielorybów (WOA), który optymalizuje parametry VMD. Następnym krokiem po dekompozycji AVMD, było obliczenie skorelowanej kurtozy składowych modalnych otrzymanych na drodze tej dekompozycji. Składniki modalne o najwyższych wartościach skorelowanej kurtozy wykorzystano do przeprowadzenia analizy obwiedni. Błąd złożony wykrywano na podstawie widma obwiedni. Skuteczność proponowanej metody sprawdzono przeprowadzając doświadczenie na przekładni, w której występował błąd złożony. Wyniki eksperymentu pokazują, że proponowane podejście stanowi skuteczną metodę wykrywania złożonych błędów.
Źródło:
Eksploatacja i Niezawodność; 2020, 22, 1; 161-169
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal conductivity of a Brown Earth soil as affected by biochars derived at different temperatures: Experiment and prediction with the Campbell model
Autorzy:
Zhao, B.
Li, L.
Zhao, Y.
Zhang, X.
Powiązania:
https://bibliotekanauki.pl/articles/2082959.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
biochar
bulk density
thermal conductivity
Brown Earth soil
Campbell model
Opis:
Thermal conductivity is a significant heat transfer property of soil. However, the influence of biochar on this property is not well known. In this research, the influence of corn straw biochars prepared at 300, 500 and 700oC on the thermal conductivity of a Brown Earth (Hapli-Udic Cambisol, FAO) soil and its prediction using a Campbell model was examined. The outcomes revealed that the bulk densities of the soil markedly decreased with increases in the biochar amendment rates of 1, 3, and 5% in linear patterns. The reduction in bulk density was mainly attributed to an increase in soil porosity and organic carbon content. With increasing volumetric water contents (10, 20, 30 and 40%), the thermal conductivity of the soils significantly increased, whereas those of soils with biochar amendment were obviously less than that of the CK and the differences increased with the biochar application rates. The pyrolysis temperature of biochar exhibited a negligible effect on the bulk density and thermal conductivity of soils at large. Combining the linear reduction of bulk density with the biochar amendment rate into the Campbell model, well-fitting results for the variation inthermal conductivity versus volumetric water content were obtained and accurate values could be predicted.
Źródło:
International Agrophysics; 2020, 34, 4; 433-439
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The direct and indirect effect of fire on radial growth of Pinus koraiensis trees in a northern temperate forest of China
Autorzy:
Gao, Lushuang
Zhang, Chunyu
Zhao, Xiuhai
Zhang, Li
Powiązania:
https://bibliotekanauki.pl/articles/956863.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
burned trees
growth pattern
competition
climate
korean pine
Opis:
The long-term effects of fire on the radial growth of Korean pines (Pinus koraiensis) in Changbai Mountain is poorly understood. In order to quantify the impact of fire on the radial growth of Korean pines, we measured ring widths and developed two tree-ring chronologies from 21 burned Korean pine trees that were damaged by fire in 1857 as well as 30 control trees in the Changbai Mountain Nature Reserve, China. As expected, the growth rates of the burned trees were slower than those of the control trees in the first five years following the fire. However, beginning six years after the fire, the growth of the burned trees increased considerably, and this period of increased growth lasted 13 years, with moderate growth occurring throughout the 1866 to 1871 period. A difference in growth rates between burned and control tress was also observed for the 20 years since temperatures began markedly increasing in 1980. Burned trees tended to respond negatively to monthly minimum temperature, precipitation, and vapor pressure deficits (VPD), whereas the positive relationship between those factors and radial growth of control trees became stronger. In addition, the significantly negative effect of competition on radial growth was only observed among burned trees. These results demonstrated that the negative and direct effect of damage to physiological plant processes by fire only affected the years shortly after a fire occurred and then became obscured by its indirect effects, such as differential responses to climate and competition, which did persist for a long time. The indirect effect on radial growth over time could be explained by the variability in the relative strength of climatic responses and competition caused by fire.
Źródło:
Dendrobiology; 2017, 78; 111-123
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical modeling of hydrodynamic and sediment siltation due to typhoon in estuary channel regulation
Autorzy:
Zhao, H.
Zhang, Q.
Xie, M.
Powiązania:
https://bibliotekanauki.pl/articles/259087.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
Oujiang Estuary
numerical model
channel regulation
sediment siltation
typhoon
Opis:
Oujiang Estuary is a complex tidal estuary with many channels and shoals in the East China Sea, which was affected by typhoon frequently. The navigation channel of Wenzhou Port is located in the north branch of Oujiang Estuary, which happened serious sediment siltation in many times due to typhoon impact. The regulation is considered to decrease siltaion of the channel and protect shoals as well. According to the site survey data, the mathematic model is established and validated, which simulates the hydrodynamic, sediment transport and channel siltation due to typhoon in Oujiang Estuary. The channel regulation scenario is studied by the model simulation after analysis of the silation character. It indicates that the high concentration sediment from shoals north of channel is main sediment source caused siltation in the channel, which can be prevented into the channel by the regulation scenario and decrease siltation efficiently.
Źródło:
Polish Maritime Research; 2015, S 1; 61-66
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on vibration evolution of a ball bearing without the cage under local variable-diameter raceway damage
Autorzy:
Zhou, Enwen
Zhao, Yanling
Zhang, Huanqing
Powiązania:
https://bibliotekanauki.pl/articles/2200877.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
ball bearing
vibration evolution
variable-diameter raceway
damage
Opis:
This article presents an analysis of vibration evolution of a ball bearing without the cage. A vibration model in which time-varying displacement, time-varying stiffness, contact force and collision force are comprehensively considered, is proposed. On this basis, the law of motion of the bearing is studied. It is shown that a variable-diameter raceway affects the radius of curvature, which effects the dispersion of rolling elements. The damaged variable -diameter raceway leads to discrete failure, contact force and collision force of rolling elements, which are main reasons that cause vibration mutation. The bearing motion changes from quasi-periodic to chaotic motion.
Źródło:
Journal of Theoretical and Applied Mechanics; 2023, 61, 1; 129--146
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prefabricated fractured rock under stepwise loading and unloading
Autorzy:
Zhang, Wei
Zhao, Tongbin
Yin, Yanchun
Powiązania:
https://bibliotekanauki.pl/articles/2086954.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
fractured rock
graded loading and unloading
rock deformation
energy evolution
acoustic emission
Opis:
After the engineering rock mass has been affected by comprehensive effects of mining and disturbance, it experiences an input of external energy as well as dissipation and release of internal energy. From the viewpoint of energy, characteristics of rock failure are studied, and the law of rock unstable deformation and energy evolution is analyzed. The damage mechanism of rock is revealed easily. A gradual loading and unloading test of fractured rock is carried out to analyze deformation characteristics of the fractured rock during the load- -bearing process, and to study the law of energy dissipation and release under different load- ing and unloading stress levels. The results show that: (1) the load-bearing time, loading and unloading stress level, stress at crack initiation and peak stress of fractured rock gradually decrease with an increase in the number of cracks, and the descending speed decreases grad- ually with the increase in the number of cracks; (2) the strain at crack initiation and peak strain of the fractured rock increase gradually with an increase in the number of cracks, and the gathering speed decreases with the increase of the number of cracks; (3) the released strain energy and dissipation energy of fractured rock increase with an increase of loading and unloading stress levels, and the increasing rate gradually slows down; (4) the number of acoustic emission events is positively related to the degree of rock damage, and the increase in the number of cracks will prolong duration of the number of acoustic emission events. The results have a theoretical value for energy evolution and deformation damage of fractured rock masses, and also provide experimental experience to study the instability precursor information of rock materials from the viewpoint of energy.
Źródło:
Journal of Theoretical and Applied Mechanics; 2022, 60, 1; 167--179
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
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/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:
Laser frequency stability estimation and velocity measurement in the atmosphere with self-heterodyne
Autorzy:
Zhang, H.
Wang, H.
Zhao, S.
Powiązania:
https://bibliotekanauki.pl/articles/174066.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
frequency stability
atmospheric propagation
self-heterodyne
Doppler velocity
Opis:
We present a novel method of self-heterodyne for laser frequency stability estimation in the atmosphere. At the same time, it is used in the Doppler velocity measurement for moving targets in the atmosphere. The transmission range is 16.2 km (round-trip propagation with 8.1 km) in the horizontal atmospheric path, and the measuring results showed that the frequency stability of the whole laser detection system is 53.4 kHz with 20.7 kHz stand deviation. This frequency stability is the integrated influence with the whole detection system not just for the laser, but it can be considered as the estimation of the laser’s frequency stability. It is much more practical for the heterodyne detection in the atmosphere. At last, the method of self-heterodyne was used for 16.2 km round trip velocity measurement. It is showed that the velocity absolute error is less than 1.5 cm/s in the turbulent atmosphere, and the relative error is not higher than 5%.
Źródło:
Optica Applicata; 2016, 46, 2; 305-316
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hybrid methodology of degradation feature extraction for bearing prognostics
Metodyka hybrydowa ekstrakcji cech degradacji do zastosowań w prognozowaniu czasu życia łożysk
Autorzy:
Gu, H.
Zhao, J.
Zhang, X.
Powiązania:
https://bibliotekanauki.pl/articles/302055.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
ekstrakcja cech
degradacja
sygnał
łożysko
feature extraction
degradation
signal
bearing
Opis:
Hybrid methodology of degradation feature extraction was presented which may enable prediction of remaining useful life of a product. In this methodology, firstly, the signal was de-noised by wavelet analysis. Then the autoregressive model was used to remove the discrete frequencies from de-noised signal. Further, the residual signal which mainly contained impulsive fault signal was enhanced by minimum entropy deconvolution filter. The kurtosis was extracted which was taken as the feature for prognostics. At last, the empirical mode decomposition was used to reduce fluctuation of feature value and to extract the trend content. A case study was presented to verify the effectiveness of the proposed method.
Przedstawiono hybrydową metodę ekstrakcji cech degradacji, która umożliwia przewidywanie pozostałego okresu użytkowania produktu. W tej metodyce, sygnał został najpierw odfiltrowany z wykorzystaniem analizy falkowej. Następnie, za pomocą modelu autoregresyjnego usunięto z pozbawionego szumów sygnału częstotliwości dyskretne. W dalszej kolejności, sygnał resztkowy, który zawierał głównie impulsowy sygnał uszkodzenia został wzmocniony z zastosowaniem filtru dekonwolucji minimum entropii. Obliczono kurtozę, którą przyjęto jako cechę w procesie prognozowania. Na koniec, zastosowano empiryczną dekompozycję sygnału (EMD) w celu zmniejszenia wahań wartości cechy oraz w celu ekstrakcji trendu. Studium przypadku demonstruje efektywność proponowanej metody.
Źródło:
Eksploatacja i Niezawodność; 2013, 15, 2; 195-201
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
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

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