An efficient approach for significant time intervals of frequent itemsets

Author(s):  
Somaraju Suvvari ◽  
R.B.V. Subramanyam
2016 ◽  
Vol 43 (1) ◽  
pp. 103-121 ◽  
Author(s):  
MohammadSadegh Zahedi ◽  
Abolfazl Aleahmad ◽  
Maseud Rahgozar ◽  
Farhad Oroumchian ◽  
Arastoo Bozorgi

Blogs are one of the main user-generated contents on the web and are growing in number rapidly. The characteristics of blogs require the development of specialized search methods which are tuned for the blogosphere. In this paper, we focus on blog retrieval, which aims at ranking blogs with respect to their recurrent relevance to a user’s topic. Although different blog retrieval algorithms have already been proposed, few of them have considered temporal properties of the input queries. Therefore, we propose an efficient approach to improving relevant blog retrieval using temporal property of queries. First, time sensitivity of each query is automatically computed for different time intervals based on an initially retrieved set of relevant posts. Then a temporal score is calculated for each blog and finally all blogs are ranked based on their temporal and content relevancy with regard to the input query. Experimental analysis and comparison of the proposed method are carried out using a standard dataset with 45 diverse queries. Our experimental results demonstrate that, using different measurement criteria, our proposed method outperforms other blog retrieval methods.


Author(s):  
Weigang Huo ◽  
Xingjie Feng ◽  
Zhiyuan Zhang

Keeping the generated fuzzy frequent itemsets up-to-date and discovering the new fuzzy frequent itemsets are challenging problems in dynamic databases. In this paper, the classical H-struct structure is extended to mining fuzzy frequent itemsets. The extended H-mine algorithm can use any t-norm operator to calculate the support of fuzzy itemset. The FP-tree-based structure called the Initial-FP-tree and the New-FP-tree are built to maintain the fuzzy frequent itemsets in the original database and the new inserted transactions respectively. The strategy of incremental mining of fuzzy frequent itemsets is achieved by breath-first-traversing the Initial-FP-tree and the New-FP-tree. All of the fuzzy frequent itemsets in the updated database can be obtained by traversing the Initial-FP-tree. The experiments on real datasets show that the proposed approach runs faster than the batch extended H-mine algorithm. Comparing with the existing algorithm for incremental mining fuzzy frequent itemsets, the proposed approach is superior in terms of the execution time. The memory cost of the proposed approach is lower than that of the existing algorithm when the minimum support threshold is low.


Cephalalgia ◽  
1984 ◽  
Vol 4 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Jan Dalkvist ◽  
Karl Ekbom ◽  
Elisabet Waldenlind

Self-ratings with respect to headache and five mood dimensions were obtained twice daily from five patients suffering from migraine and six patients suffering from muscle-contraction headache during a mean period of 47.9 days (range: 38–61). The data were analysed by multiple regression, with the rated headache as dependent variable. Different time intervals between measurement of the independent variables and measurement of the dependent variable were used. A significant time-dependent relation was found between the migraine ratings and the alertness ratings. Significant time-dependent relations were also found between rated muscle-contraction headache and rated anger and alertness, respectively, but the trends were not very pronounced. In the case of no time lag, rated muscle-contraction headache tended to be negatively related to rated alertness, happiness and concentration. Significant periodic trends were found for both the migraine and the muscle-contraction headache. The major findings are discussed in terms of stress and biological rhythms.


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