At present, near-surface shear wave velocities are mainly calculated through Rayleigh wave dispersion-curve inversions in engineering surface investigations, but the required calculations pose a highly nonlinear globa...At present, near-surface shear wave velocities are mainly calculated through Rayleigh wave dispersion-curve inversions in engineering surface investigations, but the required calculations pose a highly nonlinear global optimization problem. In order to alleviate the risk of falling into a local optimal solution, this paper introduces a new global optimization method, the shuffle frog-leaping algorithm （SFLA）, into the Rayleigh wave dispersion-curve inversion process. SFLA is a swarm-intelligence-based algorithm that simulates a group of frogs searching for food. It uses a few parameters, achieves rapid convergence, and is capability of effective global searching. In order to test the reliability and calculation performance of SFLA, noise-free and noisy synthetic datasets were inverted. We conducted a comparative analysis with other established algorithms using the noise-free dataset, and then tested the ability of SFLA to cope with data noise. Finally, we inverted a real-world example to examine the applicability of SFLA. Results from both synthetic and field data demonstrated the effectiveness of SFLA in the interpretation of Rayleigh wave dispersion curves. We found that SFLA is superior to the established methods in terms of both reliability and computational efficiency, so it offers great potential to improve our ability to solve geophysical inversion problems.展开更多
The concept of travelling wave reactor(TWR)applies the mechanism of self-sustaining and propagating nuclear fission travelling waves in fertile media of 238U and 232Th to achieve very high fuel utilization.Based on th...The concept of travelling wave reactor(TWR)applies the mechanism of self-sustaining and propagating nuclear fission travelling waves in fertile media of 238U and 232Th to achieve very high fuel utilization.Based on this concept,a stepwise radial fuel shuffling strategy was proposed and applied to a sodium-cooled fast reactor(SFR)loading metallic 238U fuel.The multi-group deterministic neutronic code ERANOS with JEFF3.1 data library was used as a basic tool to perform the neutronics and burnup calculations.The inward fuel shuffling calculations were first performed in a 1-D cylindrical case for parametric understanding,and then extended to a 2-D R-Z case.The shuffling calculations for the 1-D and 2-D SFR model yielded some interesting results.The asymptotic keff varied parabolically with the characteristic fluence,while the burnup increased linearly.The highest burnup achieved in 2-D case was 38%.The power peak shifted from the fuel outlet side(core centre)to the fuel inlet side(core periphery)in both 1-D and 2-D cases and the corresponding peaking factor decreased dramatically along with the characteristic fluence.The present research demonstrated that the proposed stepwise radial fuel shuffling in the sodium fast reactor achieved the characteristics of the traveling wave reactor.展开更多
In the application of multiple-processor systems some processors or links in a system maynot function properly,thus the fault diagnosis is one of the most important issues in the analysisand maintenance of those syste...In the application of multiple-processor systems some processors or links in a system maynot function properly,thus the fault diagnosis is one of the most important issues in the analysisand maintenance of those systems.For the practical fault diagnosis systems,the probability that allneighboring processors of a processor are faulty simultaneously is very small.Thus,the conditionaldiagnosability,which is a new metric for evaluating such systems,assumes that every fault set doesnot contain all neighbors of any processor in the system.In this paper,the authors show that then-dimensional shuffle-cube has the conditional diagnosability of 4n-15 for n = 2 (mod 4) and n ≥ 10.展开更多
基金supported by the National Natural Science Foundation of China(No.41374123)
文摘At present, near-surface shear wave velocities are mainly calculated through Rayleigh wave dispersion-curve inversions in engineering surface investigations, but the required calculations pose a highly nonlinear global optimization problem. In order to alleviate the risk of falling into a local optimal solution, this paper introduces a new global optimization method, the shuffle frog-leaping algorithm （SFLA）, into the Rayleigh wave dispersion-curve inversion process. SFLA is a swarm-intelligence-based algorithm that simulates a group of frogs searching for food. It uses a few parameters, achieves rapid convergence, and is capability of effective global searching. In order to test the reliability and calculation performance of SFLA, noise-free and noisy synthetic datasets were inverted. We conducted a comparative analysis with other established algorithms using the noise-free dataset, and then tested the ability of SFLA to cope with data noise. Finally, we inverted a real-world example to examine the applicability of SFLA. Results from both synthetic and field data demonstrated the effectiveness of SFLA in the interpretation of Rayleigh wave dispersion curves. We found that SFLA is superior to the established methods in terms of both reliability and computational efficiency, so it offers great potential to improve our ability to solve geophysical inversion problems.
基金supported by the National Natural Science Foundation of China(Grant No.11105103)the Doctoral Fund of the Ministry of Education of China(Grant No.20110201120046)
文摘The concept of travelling wave reactor(TWR)applies the mechanism of self-sustaining and propagating nuclear fission travelling waves in fertile media of 238U and 232Th to achieve very high fuel utilization.Based on this concept,a stepwise radial fuel shuffling strategy was proposed and applied to a sodium-cooled fast reactor(SFR)loading metallic 238U fuel.The multi-group deterministic neutronic code ERANOS with JEFF3.1 data library was used as a basic tool to perform the neutronics and burnup calculations.The inward fuel shuffling calculations were first performed in a 1-D cylindrical case for parametric understanding,and then extended to a 2-D R-Z case.The shuffling calculations for the 1-D and 2-D SFR model yielded some interesting results.The asymptotic keff varied parabolically with the characteristic fluence,while the burnup increased linearly.The highest burnup achieved in 2-D case was 38%.The power peak shifted from the fuel outlet side(core centre)to the fuel inlet side(core periphery)in both 1-D and 2-D cases and the corresponding peaking factor decreased dramatically along with the characteristic fluence.The present research demonstrated that the proposed stepwise radial fuel shuffling in the sodium fast reactor achieved the characteristics of the traveling wave reactor.
基金supported by the National Natural Science Foundation of China under Grant Nos. 10701074,10531070, 10771209, and 10721101in part by Sciences Foundation for Young Scholars of Beijing Normal University+1 种基金in part by priority discipline of Beijing Normal Universityin part by Chinese Academy of Sciences under Grant No. kjcx-yw-s7
文摘In the application of multiple-processor systems some processors or links in a system maynot function properly,thus the fault diagnosis is one of the most important issues in the analysisand maintenance of those systems.For the practical fault diagnosis systems,the probability that allneighboring processors of a processor are faulty simultaneously is very small.Thus,the conditionaldiagnosability,which is a new metric for evaluating such systems,assumes that every fault set doesnot contain all neighbors of any processor in the system.In this paper,the authors show that then-dimensional shuffle-cube has the conditional diagnosability of 4n-15 for n = 2 (mod 4) and n ≥ 10.
