The leakage of hazardous gases poses a significant threat to public security and causes environmental *** effective and accurate source term estimation(STE)is necessary when a leakage accident ***,most research genera...
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The leakage of hazardous gases poses a significant threat to public security and causes environmental *** effective and accurate source term estimation(STE)is necessary when a leakage accident ***,most research generally assumes that no obstacles exist near the leak source,which is inappropriate in practical *** solve this problem,we propose two different frameworks to emphasize STE with obstacles based on artificial neural network(ANN)and convolutional neural network(CNN).Firstly,we build a CFD model to simulate the gas diffusion in obstacle scenarios and construct a benchmark ***,we define the structure of ANN by searching,then predict the concentration distribution of gas using the searched model,and optimize source term parameters by particle swarm optimization(PSO)with well-performed cost ***,we propose a one-step STE method based on CNN,which establishes a link between the concentration distribution and the location of ***,we propose a novel data processing method to process sensor data,which maps the concentration information into feature *** comprehensive experiments illustrate the performance and efficiency of the proposed methods.
Dissociation of methyl nitrite is the first step during CO catalytic coupling to dimethyl oxalate followed by hydrogenation to ethyl glycol in a typical coal to liquid process. In this work, the first-principle calcul...
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Dissociation of methyl nitrite is the first step during CO catalytic coupling to dimethyl oxalate followed by hydrogenation to ethyl glycol in a typical coal to liquid process. In this work, the first-principle calculations based on density functional theory were performed to explore the reaction mechanism for the non-catalytic dissociation of methyl nitrite in the gas phase and the catalytic dissociation of methyl nitrite on Pd(111) surface since palladium supported on alpha-alumina is the most effective catalyst for the coupling. For the non-catalytic case, the calculated results show that the CH_3O–NO bond will break with a bond energy of 1.91 eV, and the produced CH_3O radicals easily decompose to formaldehyde, while the further dissociation of formaldehyde in the gas phase is difficult due to the strong C–H bond. On the other hand, the catalytic dissociation of methyl nitrite on Pd(111) to the adsorbed CH_3O and NO takes place with a small energy barrier of 0.03 eV. The calculated activation energies along the proposed reaction pathways indicate that(i) at low coverage, a successive dehydrogenation of the adsorbed CH_3O to CO and H is favored while(ii) at high coverage, hydrogenation of CH_3O to methanol and carbonylation of CH_3O to methyl formate are more preferred. On the basis of the proposed reaction mechanism,two meaningful ways are proposed to suppress the dissociation of methyl nitrate during the CO catalytic coupling to dimethyl oxalate.
In this paper,the finite-time boundedness（FTB） problem of sliding mode control（SMC） is investigated for a class of switched delay systems subject to uncertain parameter and nonlinear perturbation.A SMC law is cons...
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ISBN:
(纸本)9781538629185
In this paper,the finite-time boundedness（FTB） problem of sliding mode control（SMC） is investigated for a class of switched delay systems subject to uncertain parameter and nonlinear perturbation.A SMC law is constructed to drive the state trajectories onto the integral sliding surface during a finite time *** FTB of the controlled systems on both reaching phase and siding motion phase are analyzed by means of average dwell time ***,a numerical example is given.
Several metal terephthalates were synthesized by hydrothermal solvent method. Firstly, the coordination type of metal ions and carboxylates in terephthalate was studied by FTIR spectroscopy. The results showed that th...
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Several metal terephthalates were synthesized by hydrothermal solvent method. Firstly, the coordination type of metal ions and carboxylates in terephthalate was studied by FTIR spectroscopy. The results showed that the binding type of zinc terephthalate and aluminum terephthalate are mainly bridged coordination, while the chelating coordination mode dominated in the magnesium terephthalate and cerium terephthalate. Secondly, the thermal decomposition mechanism of zinc terephthalate in nitrogen atmosphere was studied by TG and Py-GC/MS techniques. Finally, the activation energy of the thermal decomposition process was obtained by the Friedman method and the Flynn-Wall-Ozawa(FWO) method, and the most probabilistic function was obtained by multiple linear fitting. The results showed that the decomposition process of zinc terephthalate was an one-step reaction and the activation energy was equal to 187.38 kJ/mol.
Dear Editor,In this letter,the multi-objective optimal control problem of nonlinear discrete-time systems is investigated.A data-driven policy gradient algorithm is proposed in which the action-state value function is...
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Dear Editor,In this letter,the multi-objective optimal control problem of nonlinear discrete-time systems is investigated.A data-driven policy gradient algorithm is proposed in which the action-state value function is used to evaluate the *** the policy improvement process,the policy gradient based method is employed.
This study concentrates on solving the output consensus problem for a class of heterogeneous uncertain nonstrict-feedback nonlinear multi-agent systems under switching-directed communication topologies,in which all fo...
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This study concentrates on solving the output consensus problem for a class of heterogeneous uncertain nonstrict-feedback nonlinear multi-agent systems under switching-directed communication topologies,in which all followers are subjected to multi-type input constraints such as unknown asymmetric saturation,unknown dead-zone and their integration.A unified representation is presented to overcome the difficulties originating from multi-agent input ***,the uncertain system functions in a non-lower triangular form and the interaction terms among agents are dealt with by exploiting the fuzzy logic systems and their special ***,by introducing a nonlinear filter to alleviate the problem of“explosion of complexity”during the backstepping design,a distributed common adaptive control protocol is proposed to ensure that the synchronization errors converge to a small neighborhood of the origin despite the existence of multiple input constraints and arbitrary switching communication *** stability analysis and simulation results are conducted to show the effectiveness and performance of the proposed control methodology.
Training sample selection is widely accepted as an important step in developing a near-infrared(NIR) spectroscopic model. For industrial applications, the initial training dataset is usually selected empirically. This...
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Training sample selection is widely accepted as an important step in developing a near-infrared(NIR) spectroscopic model. For industrial applications, the initial training dataset is usually selected empirically. This process is time-consuming, and updating the structure of the modeling dataset online is difficult. Considering the static structure of the modeling dataset, the performance of the established NIR model could be degraded in the online process. To cope with this issue, an active training sample selection and updating strategy is proposed in this work. The advantage of the proposed approach is that it can select suitable modeling samples automatically according to the process information. Moreover, it can adjust model coefficients in a timely manner and avoid arbitrary updating effectively. The effectiveness of the proposed method is validated by applying the method to an industrial gasoline blending process.
Microgrid is an advanced application of distributed renewable energy utilization. With the development of energy Internet technology, microgrid is characterized by strong decentralization and high intelligence. The op...
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This paper proposes a sliding mode estimation-based control to solve the stochastic time delay problem in networked microgrid,because stochastic delay has a great impact on the stability and performance of large power...
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ISBN:
(纸本)9781538629185
This paper proposes a sliding mode estimation-based control to solve the stochastic time delay problem in networked microgrid,because stochastic delay has a great impact on the stability and performance of large power grids（LPG）.To analyze the delay effects,the microgrid system model is derived according to the characteristics of the inverter in grid-connected *** on the microgrid system model,the stochastic delay estimation with learning parameter and delayed states are *** control signal designed by sliding mode control（SMC） and the learning parameter of delay estimation are adaptively changed in the sliding mode estimation-based control *** reaching law（ERL） is proposed to solve the chattering issues of *** 3.3 KW microgrid parameters are added into simulation to verify the effectiveness and performance of the proposed control strategy.
A discrete artificial bee colony algorithm is proposed for solving the blocking flow shop scheduling problem with total flow time criterion. Firstly, the solution in the algorithm is represented as job permutation. Se...
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A discrete artificial bee colony algorithm is proposed for solving the blocking flow shop scheduling problem with total flow time criterion. Firstly, the solution in the algorithm is represented as job permutation. Secondly, an initialization scheme based on a variant of the NEH heuristic and a local search is designed to construct the initial population with both quality and diversity. Thirdly, based on the idea of iterated greedy algorithm, some newly designed schemes for employed bee, onlooker bee and scout bee are presented. The performance of the proposed algorithm is tested on the well-known Taillard benchmark set, and computational results demonstrate the effectiveness of the discrete artificial bee colony algorithm. In addition, the best known solutions of the benchmark set are provided for the blocking flow shop scheduling problem with total flow time criterion.
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