A DEM-CFD coupled approach were proposed to joint the advantage of discrete models of providing detailed packing information and continuous models of realizing macro-scale simulations. DEM simulation of particle packi...
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ISBN:
(纸本)9788874317271
A DEM-CFD coupled approach were proposed to joint the advantage of discrete models of providing detailed packing information and continuous models of realizing macro-scale simulations. DEM simulation of particle packing in a small-scale fixed bed was first validated, then the model was used on particle packing in a lab-scale fixed bed with internals, statistics voidage distribution was obtained and coupled with Eulerian Granular Multiphase Model, realized the maro-scale simulation of fixed beds of considering the meso-scale packing structure.
In order to achieve the lateral control of the intelligent vehicle, use the bi-cognitive model based on cloud model and cloud reasoning, solve the decision problem of the qualitative and quantitative of the lateral co...
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In order to achieve the lateral control of the intelligent vehicle, use the bi-cognitive model based on cloud model and cloud reasoning, solve the decision problem of the qualitative and quantitative of the lateral control of the intelligent vehicle. Obtaining a number of experiment data by driving a vehicle, classify the data according to the concept of data and fix the input and output variables of the cloud controller, design the control rules of the cloud controller of intelligent vehicle, and clouded and fix the parameter of cloud controller： expectation, entropy and hyper entropy. In order to verify the effectiveness of the cloud controller, joint simulation platform based on Matlab/Simulink/CarSim is established. Experimental analysis shows that： driver＇s lateral controller based on cloud model is able to achieve tracking of the desired angle, and achieve good control effect, it also verifies that a series of mental activities such as feeling, cognition, calculation, decision and so on are fuzzy and uncertain.
作者：
李犇陈景标Institute of Quantum Electronics
and State Key Laboratory of Advanced Optical Communication System ~z Network School of Electronics Engineering & Computer Science Peking University Beijing 100871
The quantum phase transition from the Mott insulator to the superfluid phases of the bosonic atoms trapped in an optical lattice, in which the on-site interaction carl be tuned by a Feshbach resonance, is investigated...
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The quantum phase transition from the Mott insulator to the superfluid phases of the bosonic atoms trapped in an optical lattice, in which the on-site interaction carl be tuned by a Feshbach resonance, is investigated by a variational approach within mean-field theory. We derive an extended Bos^Hubbard model to describe this ultracold atomic system. By theoretical calculation and analysis, the phase diagram is shown clearly, and we find an exciting and novel phenomenon that is the appearance of the Mort insulator-sea （MI-sea）. Meanwhile, the experimental feasibility of observing the MI-sea is discussed by analyzing the published data related to the Fashbaeh resonance at present. Finally, the potential application of the MI-sea for quantum information processing and quantum computation is also discussed in detail
A generalized non-affine nonlinear power system model is presented for a single machine bus power system with a Static Var Compensator(SVC)or state Var system(SVS)for hybrid Unmanned Aerial Vehicles(UAVs).The model is...
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A generalized non-affine nonlinear power system model is presented for a single machine bus power system with a Static Var Compensator(SVC)or state Var system(SVS)for hybrid Unmanned Aerial Vehicles(UAVs).The model is constructed by differential algebraic equations on the MATLAB-Simulink platform with the programming technique of its *** the inverse system method and the Linear Quadratic Regulation(LQR),an optimized SVC controller is *** simulations under three fault conditions show that the proposed controller can effectively improve the power system transient performance.
From point of view of physics, especially of mechanics, we briefly introduce fractional operators (with emphasis on fractional calculus and fractional differential equa- tions) used for describing intermediate process...
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From point of view of physics, especially of mechanics, we briefly introduce fractional operators (with emphasis on fractional calculus and fractional differential equa- tions) used for describing intermediate processes and critical phenomena in physics and mechanics, their progress in theory and methods and their applications to modern me- chanics. Some authors’ researches in this area in recent years are included. Finally, prospects and evaluation for this subject are made.
Driver's collision avoidance performance has a direct link to the collision risk and crash severity. Previous studies demonstrated that the distracted driving, such as using a cell phone while driving, disrupted t...
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Driver's collision avoidance performance has a direct link to the collision risk and crash severity. Previous studies demonstrated that the distracted driving, such as using a cell phone while driving, disrupted the driver's performance on road. This study aimed to investigate the manner and extent to which cell phone use and driver's gender affected driving performance and collision risk in a rear-end collision avoidance process. Forty-two licensed drivers completed the driving simulation experiment in three phone use conditions: no phone use, hands-free, and hand-held, in which the drivers drove in a car-following situation with potential rear-end collision risks caused by the leading vehicle's sudden deceleration. Based on the experiment data, a rear-end collision risk assessment model was developed to assess the influence of cell phone use and driver's gender. The cell phone use and driver's gender were found to be significant factors that affected the braking performances in the rear-end collision avoidance process, including the brake reaction time, the deceleration adjusting time and the maximum deceleration rate. The minimum headway distance between the leading vehicle and the simulator during the rear-end collision avoidance process was the final output variable, which could be used to measure the rear-end collision risk and judge whether a collision occurred. The results showed that although cell phone use drivers took some compensatory behaviors in the collision avoidance process to reduce the mental workload, the collision risk in cell phone use conditions was still higher than that without the phone use. More importantly, the results proved that the hands-free condition did not eliminate the safety problem associated with distracted driving because it impaired the driving performance in the same way as much as the use of hand-held phones. In addition, the gender effect indicated that although female drivers had longer reaction time than male drivers in
In simulation grid, information sharing is very important for the grid units to cooperate with each other effectively and efficiently. In this paper, to resolve the problem of semantic heterogeneity, an ontology-based...
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ISBN:
(纸本)9780889869264
In simulation grid, information sharing is very important for the grid units to cooperate with each other effectively and efficiently. In this paper, to resolve the problem of semantic heterogeneity, an ontology-based approach is proposed. In this approach, firstly, the local ontologies are merged into a global ontology based on their similarities. Then, with the merged global ontology, the semantic heterogeneity is resolved by comparing the classes and attributes of the local information source schemas. An example of how to resolve semantic heterogeneity in the E-government simulation grid is presented to illustrate this approach.
After being pumped from the 5s_(1/2) ground state to the 6p_(1/2) state,the population inversion between 6s_(1/2) and 5p_(1/2,3/2) can be established for a rubidium four-level active optical *** calculate the ac Stark...
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After being pumped from the 5s_(1/2) ground state to the 6p_(1/2) state,the population inversion between 6s_(1/2) and 5p_(1/2,3/2) can be established for a rubidium four-level active optical *** calculate the ac Stark shift due to lattice trapping laser which dominates the frequency shift of clock transition in a lattice trapped rubidium four-level active optical *** magic wavelengths are found,which can form desired optical lattice trapping *** choosing a proper intensity and linewidth of the trapping laser,the fractional frequency uncertainty of clock transition due to the ac Stark shift of the trapping laser,is estimated to be below 10^(−18).
The task template system of this system combines the business requirements of the work and provides the classification management function of work packages and work package templates. At the same time, data integratio...
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Nonlinear spectroscopy has become a useful tool in laser cooling,frequency stabilization and so *** use the 455.5 nm light beam output of an external cavity diode laser to perform the saturation spectroscopy signal an...
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Nonlinear spectroscopy has become a useful tool in laser cooling,frequency stabilization and so *** use the 455.5 nm light beam output of an external cavity diode laser to perform the saturation spectroscopy signal and polarization spectroscopy signal on the 6S_(1/2)→7P3/2 transition in *** measured linewidth of the F4→4,5 transition is as narrow as 1.40 MHz and that of the F3→2,3 transition is 1.67 *** of them are very close to the natural linewidth of about 1.2 *** result is the narrowest measured linewidth of Cs 455 nm saturation spectroscopy signal to our knowledge.
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