The success probability of searching an objective item from an unsorted database using standard Grover's algorithm is usually not exactly 1. It is exactly 1 only when it is used to find the target state from a dat...The success probability of searching an objective item from an unsorted database using standard Grover's algorithm is usually not exactly 1. It is exactly 1 only when it is used to find the target state from a database with four items. Exact search is always important in theoretical and practical applications. The failure rate of Grover's algorithm becomes big when the database is small, and this hinders the use of the commonly used divide-and-verify strategy. Even for large database, the failure rate becomes considerably large when there are many marked items. This has put a serious limitation on the usability of the Grover's algorithm. An important improved version of the Grover's algorithm, also known as the improved Grover algorithm, solves this problem. The improved Grover algorithm searches arbitrary number of target states from an unsorted database with full success rate. Here, we give the first experimental realization of the improved Grover algorithm, which finds a marked state with certainty, in a nuclear magnetic resonance system. The optimal control theory is used to obtain an optimized control sequence. The experimental results agree well with the theoretical predictions.展开更多
This paper presents an effective approach for updating finite element dynamic model from incomplete modal data identified from ambient vibration measurements.The proposed method is based on the relationship between th...This paper presents an effective approach for updating finite element dynamic model from incomplete modal data identified from ambient vibration measurements.The proposed method is based on the relationship between the perturbation of structural parameters such as stiffness and mass changes and the modal data measurements of the tested structure such as measured mode shape readings.Structural updating parameters including both stiffness and mass parameters are employed to represent the differences in structural parameters between the finite element model and the associated tested structure.These updating parameters are then evaluated by an iterative solution procedure,giving optimised solutions in the least squares sense without requiring an optimisation technique.In order to reduce the influence of modal measurement uncertainty,the truncated singular value decomposition regularization method incorporating the quasi-optimality criterion is employed to produce reliable solutions for the structural updating parameters.Finally,the numerical investigations of a space frame structure and the practical applications to the Canton Tower benchmark problem demonstrate that the proposed method can correctly update the given finite element model using the incomplete modal data identified from the recorded ambient vibration measurements.展开更多
In this paper,a "macroscopic-scale" numerical method for drop oscillation in AC electrowetting is presented.The method is based on a high-fidelity moving mesh interface tracking(MMIT) approach and a "mi...In this paper,a "macroscopic-scale" numerical method for drop oscillation in AC electrowetting is presented.The method is based on a high-fidelity moving mesh interface tracking(MMIT) approach and a "microscopic model" for the moving contact line.The contact line model developed by Ren et al.[Phys Fluids,2010,22:102103] is used in the simulation.To determine the slip length in this model,we propose a calibration procedure using the experimental data of drop spreading in DC electrowetting.In the simulation,the frequency of input AC voltage varies in a certain range while the root-mean-square value remains fixed.The numerical simulation is validated against the experiment and it shows that the predicted resonance frequencies for different oscillation modes agree reasonably well with the experiment.The origins of discrepancy between simulation and experiment are analyzed in the paper.Further investigation is also conducted by including the contact angle hysteresis into the contact line model to account for the "stick-slip" behavior.A noticeable improvement on the prediction of resonance frequencies is achieved by using the hysteresis model.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11175094 and 91221205)the National Basic Research Program of China(Grant No.2011CB9216002)the Fund of State Key Laboratory of Intense Pulsed Radiation Simulation and Effect
文摘The success probability of searching an objective item from an unsorted database using standard Grover's algorithm is usually not exactly 1. It is exactly 1 only when it is used to find the target state from a database with four items. Exact search is always important in theoretical and practical applications. The failure rate of Grover's algorithm becomes big when the database is small, and this hinders the use of the commonly used divide-and-verify strategy. Even for large database, the failure rate becomes considerably large when there are many marked items. This has put a serious limitation on the usability of the Grover's algorithm. An important improved version of the Grover's algorithm, also known as the improved Grover algorithm, solves this problem. The improved Grover algorithm searches arbitrary number of target states from an unsorted database with full success rate. Here, we give the first experimental realization of the improved Grover algorithm, which finds a marked state with certainty, in a nuclear magnetic resonance system. The optimal control theory is used to obtain an optimized control sequence. The experimental results agree well with the theoretical predictions.
文摘This paper presents an effective approach for updating finite element dynamic model from incomplete modal data identified from ambient vibration measurements.The proposed method is based on the relationship between the perturbation of structural parameters such as stiffness and mass changes and the modal data measurements of the tested structure such as measured mode shape readings.Structural updating parameters including both stiffness and mass parameters are employed to represent the differences in structural parameters between the finite element model and the associated tested structure.These updating parameters are then evaluated by an iterative solution procedure,giving optimised solutions in the least squares sense without requiring an optimisation technique.In order to reduce the influence of modal measurement uncertainty,the truncated singular value decomposition regularization method incorporating the quasi-optimality criterion is employed to produce reliable solutions for the structural updating parameters.Finally,the numerical investigations of a space frame structure and the practical applications to the Canton Tower benchmark problem demonstrate that the proposed method can correctly update the given finite element model using the incomplete modal data identified from the recorded ambient vibration measurements.
基金supported by the Chinese Academy of Sciences(Grant Nos. KJCX-SW-L08,KJCX2-YW-H18 and KJCX3-SYW-S01)the National Basic Research Program of China(Grant No.2007CB814803)the National Natural Science Foundation of China(Grant Nos.10732090,10872201 and 11023001)
文摘In this paper,a "macroscopic-scale" numerical method for drop oscillation in AC electrowetting is presented.The method is based on a high-fidelity moving mesh interface tracking(MMIT) approach and a "microscopic model" for the moving contact line.The contact line model developed by Ren et al.[Phys Fluids,2010,22:102103] is used in the simulation.To determine the slip length in this model,we propose a calibration procedure using the experimental data of drop spreading in DC electrowetting.In the simulation,the frequency of input AC voltage varies in a certain range while the root-mean-square value remains fixed.The numerical simulation is validated against the experiment and it shows that the predicted resonance frequencies for different oscillation modes agree reasonably well with the experiment.The origins of discrepancy between simulation and experiment are analyzed in the paper.Further investigation is also conducted by including the contact angle hysteresis into the contact line model to account for the "stick-slip" behavior.A noticeable improvement on the prediction of resonance frequencies is achieved by using the hysteresis model.
