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

Neutral Higgs boson contributions to CP asymmetry of B→ΦKSB \to \Phi K_S in MSSM

We have studied the neutral Higgs boson (NHB) contributions to the pure penguin process $B\to \phi K_S$ in MSSM with middle and large $\tan\beta$ (say, $>$ 8). We show that the $\alpha_s$ order hadronic matrix elements of NHB induced operators can make sizable effects on both the branch ratio and time dependent CP asymmetry $S_{\phi K}$. Under the all relevant experimental constraints, the Higgs mediated contributions to $S_{\phi K}$ alone can provide a significant deviation from SM and, in particular, lead to a negative $S_{\phi K}$ which is reported by BaBar and Belle.Comment: 7 pages and 6 figure

CP asymmetries in B→ϕKSB\to \phi K_S and B→η′KSB\to \eta' K_S in MSSM

We study the $B\to \phi K_S$ and B\to \ep K_S decays in MSSM by calculating hadronic matrix elements of operators with QCD factorization approach and including neutral Higgs boson (NHB) contributions. We calculate the Wilson coefficients of operators including the new operators which are induced by NHB penguins at LO using the MIA with double insertions. We calculate the $\alpha_s$ order hadronic matrix elements of the new operators for $B\to \phi K_s$ and $B\to \eta^\prime K_s$. It is shown that the recent experimental results on the time-dependent CP asymmetries in $B\to \phi K_S$ and B\to \ep K_S, $S_{\phi K}$ is negative and $S_{\eta^{\prime} K}$ is positive, which can not be explained in SM, can be explained in MSSM if there are flavor non-diagonal squark mass matrix elements of 2nd and 3rd generations whose size satisfies all relevant constraints from known experiments ($B\to X_S\gamma, B_s\to \mu^+\mu^-, B\to X_s \mu^+\mu^-, B\to X_s g, \Delta M_s$, etc.). In particular, we find that one can explain the experimental results with a flavor non-diagonal mass insertion of any chirality when $\alpha_s$ corrections of hadronic matrix elements of operators are included, in contrast with the claim in the literature. At the same time, the branching ratios for the two decays can also be in agreement with experimental measurements.Comment: 21 pages, 23 figures. Some changes have been made, which include comments on contributions to $B\to \phi K_S$ and $B\to \eta' K_S$ from RR and RL insertion and some typing error