Topic tracking with Bayesian belief network

The task of topic tracking is to monitor a stream of stories and find all subsequent stories that discuss the same topic. Using Bayesian belief network we give three topic tracking models: a static topic model BSTM and two dynamic topic models BDTM-I, BDTM-II. BDTM-II merges the advantages of BSTM and BDTM-I, has better tracking performance than the former two, and effectively alleviates topic drift phenomenon. Applying unrelated coming stories to update BDTM-I and BDTM-II can filter noises existed in topics. Experiments on TDT corpora show that BSTM decreases (C_det)_norm by 5.5% comparing to VSM, BDTM-II decreases (C_det)_norm by 6.3% and 6.0% comparing to BSTM and BDTM-I respectively, using unrelated stories can improve the tracking performance.     

Geometric Phase for High-Temperature Master Equation

Geometric phase of mixed state is investigated for three-level system obeying a high-temperature master equation. The results show the Berry phase of mixed phase is strongly dependent on the initial condition. For the different initial angle, the turning region is different. In addition, the decrease of Berry phase is most slow around the coupling strength α=5 with an increasing of evolving time.     

Domino free radical photopolymerization based on phototriggered base proliferation reaction and redox initiation

A detailed evaluation of the kinetics of domino free radical photopolymerization (DFRP) based on phototriggered base proliferation reaction and redox initiation was described in the condition of eliminating the heat of polymerization via reacting in the thin polymer films. First, domino photoinitiating system made a substantial breakthrough in the photoefficiency of amine generation in contrast to photocaged base system, exhibiting marked improvement in the photosensitivity. Second, both the structural feature of base amplifier (BA) and reaction temperature as two important factors impacting the proliferation rate have been detailed. Third, different domino photoinitiating components, such as BAs, peroxides, and acrylates, were investigated in the thin polymer films. It is shown that both primary and secondary BAs are efficient catalysts for DFRP. Furthermore, polymerization rate shows a consistent dependence on the pK_a value of the proliferated amine. Finally, remarkable post conversion after irradiation was achieved in DFRP. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1560–1569