The booming development of rare earth industry and the extensive utilization of its products accompanied by urban development have led to the accelerated accumulation of rare earth elements(REEs)as emerging pollutants...
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The booming development of rare earth industry and the extensive utilization of its products accompanied by urban development have led to the accelerated accumulation of rare earth elements(REEs)as emerging pollutants in atmospheric *** this study,the variation of REEs in PM_(2.5)with urban(a non-mining city)transformation was investigated through five consecutive years of sample *** compositional variability and provenance contribution of REEs in PM_(2.5)were characterized,and the REEs exposure risks of children and adults via inhalation,ingestion and dermal absorption were also *** results showed an increase in the total REEs concentration from 46.46±35.16 mg/kg(2017)to 81.22±38.98 mg/kg(2021)over the five-year period,with Ce and La making the largest *** actual increment of industrial and traffic emission source among the three pollution sources was 1.34 ng/m^(3).Coal combustion source displayed a downward *** was the main exposure pathway for REEs in PM_(2.5)for both children and *** contributed the most to the total intake of REEs in PM_(2.5)among the population,followed by La and *** exposure risks of REEs in PM_(2.5)in the region were relatively low,but the trend of change was of great *** was strongly recommended to strengthen the concern about traffic-related non-exhaust emissions of particulate matter.
Accurate photovoltaic power forecasting(PVPF) can ensure the stability of grid operation and the reliability of economic ***,PV power generation is greatly affected by weather conditions,thus more external information...
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ISBN:
(数字)9789887581536
ISBN:
(纸本)9781665482561
Accurate photovoltaic power forecasting(PVPF) can ensure the stability of grid operation and the reliability of economic ***,PV power generation is greatly affected by weather conditions,thus more external information needs to be combined to improve the forecasting *** on the measured data and NWP data,this paper proposes a PSC-SVR model to forecast the intra-hour PV *** model consists of PV physical model(PSC) and support vector regression(SVR).PSC converts the irradiance as a priori feature of the model,including calculating the sun position,irradiance separation and transposition *** is used for the two-stage data fusion of NWP power modeling and power *** method was verified on 4 power stations in the public data set *** forecasting PV power in the next one hour,the average RMSE/MAE of all stations is 1.927 MW/1.167 MW,which decreases by 40%/55% compared with persistent model,6%/7% compared with NWP correction forecasting method,9%/13% and 32%/34% compared with the single measured data and single NWP *** above results show the effectiveness of our proposed model in multi-source data fusion and PV power forecasting.
As an advanced control method of permanent magnet synchronous motor(PMSM),finite control set model predictive control(FCS-MPC) has earned widespread attention for its advantages of intuitive concept,splendid dynamic p...
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ISBN:
(数字)9789887581536
ISBN:
(纸本)9781665482561
As an advanced control method of permanent magnet synchronous motor(PMSM),finite control set model predictive control(FCS-MPC) has earned widespread attention for its advantages of intuitive concept,splendid dynamic performance and capability of handling the constraints and ***,the dependence on the model parameter accuracy is the main barrier for FCS-MPC to be applied to the industry *** order to solve this issue,this paper presents a robust FCS-MPC against parameter *** proposed strategy utilizes the prediction error in the d-and q-axis currents during the past instant to calculate the compensation which should be added to the predicted currents in the next ***,the cost function in the proportional-integral form is designed as ***,the simulation results and experimental results prove the proposed method's effectiveness in suppressing the influence of model parameter mismatch on the control performance of PMSM.
A model predictive tracking control algorithm for rigid manipulators considering the existence of external time-varying disturbances is studied in this *** the field of manipulators,disturbances are *** the influence ...
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ISBN:
(数字)9789887581536
ISBN:
(纸本)9781665482561
A model predictive tracking control algorithm for rigid manipulators considering the existence of external time-varying disturbances is studied in this *** the field of manipulators,disturbances are *** the influence of disturbances will lead to poor control accuracy and even *** a two-degree-of-freedom(2-DoF) rigid manipulator,a composite algorithm combing model predictive control(MPC) and a generalized proportional integral observer(GPIO) is *** the proposed method,feedback linearization technology is used to decouple the *** order to improve the ability of disturbance rejection,a GPIO is used to estimate the lumped disturbances and the estimated values are added to the control law by feedforward *** is conducted to validate the proposed algorithm.
High pressure common rail(HPCR) technology has been widely applied in diesel *** tracking speed and the steady-state fluctuations of the rail pressure determine the performance of the HPCR *** this paper,the fuel inje...
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ISBN:
(数字)9789887581536
ISBN:
(纸本)9781665482561
High pressure common rail(HPCR) technology has been widely applied in diesel *** tracking speed and the steady-state fluctuations of the rail pressure determine the performance of the HPCR *** this paper,the fuel injection disturbance which has a main impact on rail pressure fluctuations is fully *** on fluid dynamics and Newtonian mechanics,a nonlinear model of the HPCR system is *** order to suppress the fuel injection disturbance,a finitetime disturbance observer(FTDO) based continuous non-singular terminal sliding mode controller(CNTSMC+FTDO) is designed based on the three-step analysis *** is proved that the system tracking error can converge to the equilibrium point in a finite ***,a group of simulations and experiments are conducted in Simulink and the more realistic AMESim environment respectively and the results verify the effectiveness and feasibility of the proposed algorithm.
This paper studies the interaction torque estimation method of the rigid robotic manipulator under the low-speed ***,a nonlinear friction model is established to analysis the influence of *** the noise into considerat...
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ISBN:
(数字)9789887581536
ISBN:
(纸本)9781665482561
This paper studies the interaction torque estimation method of the rigid robotic manipulator under the low-speed ***,a nonlinear friction model is established to analysis the influence of *** the noise into consideration,a least square identification method is ***,a finite-time extended state observer is established to estimate the interaction torque,which is capable of estimating time-varying *** stability of the system is demonstrated based on the Lyapunov *** results are given to show the effectiveness of the proposed method.
In one-stage methods for video moment retrieval,the common representations indirectly supervised by boundary prediction fail to fully preserve the inherent characteristic of the video and query,which limits the retrie...
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ISBN:
(数字)9789887581536
ISBN:
(纸本)9781665482561
In one-stage methods for video moment retrieval,the common representations indirectly supervised by boundary prediction fail to fully preserve the inherent characteristic of the video and query,which limits the retrieval *** solve this problem,an Adversarial Video Moment Retrieval(AVMR) algorithm is proposed to learn the common representations with modality invariance and cross-modal *** is implemented through the process of adversarial learning between a feature projector and a modality *** feature projector tries to generate a modality-invariant common representation and to confuse the modality *** modality classifier tries to discriminate between different modalities based on the generated representation by the feature *** triplet constraints are further imposed on the feature projector to preserve the underlying cross-modal semantic structure of *** experimental results show that AVMR surpasses the baseline Attentive Cross-modal Relevance Matching(ACRM) by 1.10% and 1.73% in the "mIoU" metric on two public datasets Charades-STA and TACoS,respectively.
The inter-class similarity of facial expressions is one of the key challenges in Facial Expression Recognition(FER).In this manuscript,a Latent Facial Action Units Network(LAUNet) is proposed for the problem of inter-...
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ISBN:
(数字)9789887581536
ISBN:
(纸本)9781665482561
The inter-class similarity of facial expressions is one of the key challenges in Facial Expression Recognition(FER).In this manuscript,a Latent Facial Action Units Network(LAUNet) is proposed for the problem of inter-class similarity of facial expressions in *** proposed method recognizes subtle differences between facial expressions by learning Latent Facial Action Units Features(LAUFs).Specifically,LAUNet is composed of two parts:the Latent Facial Action Units Features Extraction Network(LEN) and the Latent Facial Action Units Selection Network(LSN).Firstly,LEN extracts LAUFs from the feature map of the backbone using the spatial attention ***,taking advantage of the channel attention mechanism,LSN captures the latent relationships between features from LAUFs to select effective features for *** are performed on the dataset after removing the invalid data of non-face images from the original FER2013 *** with some previous state-of-the-art methods,LAUNet achieves the highest accuracy rate of 71.31%.Depending on the backbone,LAUNet can improve the accuracy by up to 5.46% compared to the original architecture of the backbone.
In this study,we propose valley phononic crystals that consist of a hexagonal aluminum plate with six chiral arrangements of *** phononic crystals were introduced into a topological insulator(TI)system to produce topo...
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In this study,we propose valley phononic crystals that consist of a hexagonal aluminum plate with six chiral arrangements of *** phononic crystals were introduced into a topological insulator(TI)system to produce topologically protected edge waves(TPEW s)along the topological *** implementation of chiral topological edge states is different from the implementation of topological edge states of systems with *** the conventional breaking of mirror symmetry,a new complete band with topological edge modes gap was opened up at the Dirac point by tuning the difference in lengths of the ligaments in the chiral unit *** investigated the dispersion properties in chiral systems and applied the dispersion properties to waveguides on the interfaces to achieve designable route ***,we simulated the robust propagation of TPEWs in different routes and demonstrated their immunity to backscattering at ***,the existence of the valley Hall effect in chiral systems was *** study findings may lead to the further study of the topological states of chiral materials.
In this paper, a hierarchical formation-containment control scheme is proposed for second-order multi-agent systems. The proposed hierarchical scheme decouples the control task into two layers, i.e., reference signal ...
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