基于模拟划分的SP-k-means-+算法

I-k-means-+算法作为一种新的k-means目标函数优化算法,通过分裂与删除簇提高解的质量,在一定程度上克服了k-means算法容易陷入局部最优解而导致目标函数优化效果不佳的问题,但该算法采用一种比较粗糙的方式估计各簇的Gain值和Cost值,影响了目标函数优化效果。针对此问题本文提出了一种基于模拟划分的SP-k-means-+算法,根据各簇模拟划分的情况,更准确地计算各簇的Gain值和Cost值,降低了簇对匹配过程中漏检与误判的可能性,在每次迭代中选择更合适的簇对执行分裂删除操作,进一步优化了目标函数并且避免了无效迭代造成的冗余计算问题。实验结果表明:当无需-+操作时,本文算法与I-kmeans-+算法的目标函数一致且效率提升了16%;当需要-+操作时,本文算法在不降低计算效率的前提下目标函数优化效果较I-k-means-+算法更佳,聚类模型解的精度提高了10%以上,最高达到47%。

CFD gas–liquid simulation of oriented valve tray

Computational fluid dynamics(CFD) has recently emerged as an effective tool for the investigation of the hydraulic parameters and efficiency of tray towers.The computation domain was established for two types of oriented valves within a tray and meshed into two parts with different grid types and sizes.The volume fraction correlation concerning inter-phase momentum transfer source was fitted based on experimental data,and built in UDF for simulation.The flow pattern of oriented valve tray under different operating conditions was simulated under Eulerian-Eulerian framework with realizable k-ε model.The predicted liquid height from CFD simulation was in good agreement with the results of pressure drop and volume fraction correlations.Meanwhile,the velocity distribution and volume fraction of the two phases were demonstrated and analyzed,which are useful in design and analysis of the column trays.

Study on the Mode of Payment Distribution About AVEs

In this paper, the fixed-payment distribution mode of Agile Virtual Enterprises （AVEs） is studied based on game theory, and the result is compared with that of the share income mode. Finally, the paper proposes that in the circumstance of manufacturing resource information web, the goal function of the game is changed thus promotes the Nash equilibrium effort level approaches or equals to the Pareto equilibrium effort level.