Optimal design of passive power filters of an asymmetrical system based on genetic algorithm

AbstractHybrid power filter is effective equipment for preventing harmonic pollution and enhancing power quality. The design of passive power filters is one of the important parts of hybrid power filter. Conventional approaches for the design of passive power filters depend on the experiences and single technology criterions, which are difficult to achieve the optimal solution. An optimal design method based on genetic algorithm is proposed in this paper. Two objectives including minimum total harmonics distortion of current and minimum cost for equipments are constructed, and reactive power compensation is used as constraint condition. The objective functions for an asymmetrical powers system are deduced, thus the fitness functions are determined. And the parameters of passive power filters are achieved by adopting genetic algorithm. Passive power filters applied in practical system are designed and the simulation model is given. Simulation results show that the filter designed by the proposed algorithm has better harmonics suppression effect and lower initial investment for equipments than conventional approaches

Degree correlation effect of bipartite network on personalized recommendation

In this paper, by introducing a new user similarity index base on the diffusion process, we propose a modified collaborative filtering (MCF) algorithm, which has remarkably higher accuracy than the standard collaborative filtering. In the proposed algorithm, the degree correlation between users and objects is taken into account and embedded into the similarity index by a tunable parameter. The numerical simulation on a benchmark data set shows that the algorithmic accuracy of the MCF, measured by the average ranking score, is further improved by 18.19% in the optimal case. In addition, two significant criteria of algorithmic performance, diversity and popularity, are also taken into account. Numerical results show that the presented algorithm can provide more diverse and less popular recommendations, for example, when the recommendation list contains 10 objects, the diversity, measured by the hamming distance, is improved by 21.90%.Comment: 9 pages, 3 figure

Effect of user tastes on personalized recommendation

In this paper, based on a weighted projection of the user-object bipartite network, we study the effects of user tastes on the mass-diffusion-based personalized recommendation algorithm, where a user's tastes or interests are defined by the average degree of the objects he has collected. We argue that the initial recommendation power located on the objects should be determined by both of their degree and the users' tastes. By introducing a tunable parameter, the user taste effects on the configuration of initial recommendation power distribution are investigated. The numerical results indicate that the presented algorithm could improve the accuracy, measured by the average ranking score, more importantly, we find that when the data is sparse, the algorithm should give more recommendation power to the objects whose degrees are close to the users' tastes, while when the data becomes dense, it should assign more power on the objects whose degrees are significantly different from user's tastes.Comment: 8 pages, 4 figure

Distribution and Permeability of Capillaries at the Skin of the Conception Vessel and the Governor Vessel in Healthy Rabbits

ObjectiveTo investigate the distribution and permeability of blood vessels on the Conception Vessel and the Governor Vessel in the physiological state.MethodsEvans blue (EB) solution was injected into the marginal ear vein of healthy rabbits. Three hours after injection, the rabbits were sacrificed and the skin on the Conception Vessel and the Governor Vessel and the corresponding bilateral non-channels was collected. EB was extracted with 7:3 acetone: physiological saline, and the absorbance of EB at each skin tissue was measured with a spectrophotometer.ResultsThe A value of EB absorbance at the Conception Vessel on the abdominal skin was lower than that of the corresponding bilateral non-channels with a statistically significant difference (P<0.01). The A value of EB absorbance at the Governor Vessel on the back was higher than that of the corresponding bilateral non-channels (P<0.05). There was no statistical difference in the A value of EB absorbance between the bilateral non-channels of the abdomen and the back (P>0.05).ConclusionThere were differences in capillary distribution and permeability between the Conception Vessel, the Governor Vessel and the corresponding bilateral non-meridians