scholarly journals Efficient parallel CP decomposition with pairwise perturbation and multi-sweep dimension tree

Author(s):  
Linjian Ma ◽  
Edgar Solomonik
Keyword(s):  
2021 ◽  
Vol 15 (3) ◽  
pp. 1-33
Author(s):  
Jingjing Wang ◽  
Wenjun Jiang ◽  
Kenli Li ◽  
Keqin Li

CANDECOMP/PARAFAC (CP) decomposition is widely used in various online social network (OSN) applications. However, it is inefficient when dealing with massive and incremental data. Some incremental CP decomposition (ICP) methods have been proposed to improve the efficiency and process evolving data, by updating decomposition results according to the newly added data. The ICP methods are efficient, but inaccurate because of serious error accumulation caused by approximation in the incremental updating. To promote the wide use of ICP, we strive to reduce its cumulative errors while keeping high efficiency. We first differentiate all possible errors in ICP into two types: the cumulative reconstruction error and the prediction error. Next, we formulate two optimization problems for reducing the two errors. Then, we propose several restarting strategies to address the two problems. Finally, we test the effectiveness in three typical dynamic OSN applications. To the best of our knowledge, this is the first work on reducing the cumulative errors of the ICP methods in dynamic OSNs.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Xiangwen Liao ◽  
Lingying Zhang ◽  
Jingjing Wei ◽  
Dingda Yang ◽  
Guolong Chen

User influence is a very important factor for microblog user recommendation in mobile social network. However, most existing user influence analysis works ignore user’s temporal features and fail to filter the marketing users with low influence, which limits the performance of recommendation methods. In this paper, a Tensor Factorization based User Cluster (TFUC) model is proposed. We firstly identify latent influential users by neural network clustering. Then, we construct a features tensor according to latent influential user’s opinion, activity, and network centrality information. Furthermore, user influences are predicted by the latent factors resulting from the temporal restrained CP decomposition. Finally, we recommend microblog users considering both user influence and content similarity. Our experimental results show that the proposed model significantly improves recommendation performance. Meanwhile, the mean average precision of TFUC outperforms the baselines with 3.4% at least.


Author(s):  
Niannan Xue ◽  
George Papamakarios ◽  
Mehdi Bahri ◽  
Yannis Panagakis ◽  
Stefanos Zafeiriou

1999 ◽  
Vol 39 (10-11) ◽  
pp. 225-230 ◽  
Author(s):  
Jong-Nan Chen ◽  
Yi-Chin Chan ◽  
Ming-Chun Lu

The decomposition of chlorophenols in aqueous solution with UV-illuminated TiO2 suspensions in the presence of manganese ions was studied. It was found that the removal rate of chlorophenols would be the highest at pH 3 in the presence of 1.18×10−4 M manganese ion. The effect of ionic strength on the 2-CP decomposition can be ignored in the range from 0.1 to 0.005 M for NaClO4. This study is also to explore the relationship between the adsorption rate and reaction rate. Results showed that the more the adsorption rate the more the decomposition rate for the three chlorophenols. Manganese ions can increase the photocatalytic oxidation of 2-chlorophenol in terms of DOC. The relationship between temperature and reaction rate for 2-CP is k = 0.0043T - 1.2146.


Sign in / Sign up

Export Citation Format

Share Document