5,198 research outputs found
An Efficient Algorithm for Frequent Pattern Mining for Real-Time Business Intelligence Analytics in Dense Datasets
Finding frequent patterns from databases has been the most time consuming process in data mining tasks, like association rule mining. Frequent pattern mining in real-time is of increasing thrust in many business applications such as e-commerce, recommender systems, and supply-chain management and group decision support systems, to name a few. A plethora of efficient algorithms have been proposed till date, among which, vertical mining algorithms have been found to be very effective, usually outperforming the horizontal ones. However, with dense datasets, the performances of these algorithms significantly degrade. Moreover, these algorithms are not suited to respond to the real-time need. In this paper, we describe BDFS(b)-diff-sets, an algorithm to perform real-time frequent pattern mining using diff-sets and limited computing resources. Empirical evaluations show that our algorithm can make a fair estimation of the probable frequent patterns and reaches some of the longest frequent patterns much faster than the existing algorithms.
Mining Frequent Graph Patterns with Differential Privacy
Discovering frequent graph patterns in a graph database offers valuable
information in a variety of applications. However, if the graph dataset
contains sensitive data of individuals such as mobile phone-call graphs and
web-click graphs, releasing discovered frequent patterns may present a threat
to the privacy of individuals. {\em Differential privacy} has recently emerged
as the {\em de facto} standard for private data analysis due to its provable
privacy guarantee. In this paper we propose the first differentially private
algorithm for mining frequent graph patterns.
We first show that previous techniques on differentially private discovery of
frequent {\em itemsets} cannot apply in mining frequent graph patterns due to
the inherent complexity of handling structural information in graphs. We then
address this challenge by proposing a Markov Chain Monte Carlo (MCMC) sampling
based algorithm. Unlike previous work on frequent itemset mining, our
techniques do not rely on the output of a non-private mining algorithm.
Instead, we observe that both frequent graph pattern mining and the guarantee
of differential privacy can be unified into an MCMC sampling framework. In
addition, we establish the privacy and utility guarantee of our algorithm and
propose an efficient neighboring pattern counting technique as well.
Experimental results show that the proposed algorithm is able to output
frequent patterns with good precision
Controlling False Positives in Association Rule Mining
Association rule mining is an important problem in the data mining area. It
enumerates and tests a large number of rules on a dataset and outputs rules
that satisfy user-specified constraints. Due to the large number of rules being
tested, rules that do not represent real systematic effect in the data can
satisfy the given constraints purely by random chance. Hence association rule
mining often suffers from a high risk of false positive errors. There is a lack
of comprehensive study on controlling false positives in association rule
mining. In this paper, we adopt three multiple testing correction
approaches---the direct adjustment approach, the permutation-based approach and
the holdout approach---to control false positives in association rule mining,
and conduct extensive experiments to study their performance. Our results show
that (1) Numerous spurious rules are generated if no correction is made. (2)
The three approaches can control false positives effectively. Among the three
approaches, the permutation-based approach has the highest power of detecting
real association rules, but it is very computationally expensive. We employ
several techniques to reduce its cost effectively.Comment: VLDB201
Failure prediction for high-performance computing systems
The failure rate in high-performance computing (HPC) systems continues to escalate as the number of components in these systems increases. This affects the scalability and the performance of parallel applications in large-scale HPC systems. Fault tolerance (FT) mechanisms help mitigating the impact of failures on parallel applications. However, utilizing such mechanisms requires additional overhead. Besides, the overuse of FT mechanisms results in unnecessarily large overhead in the parallel applications. Knowing when and where failures will occur can greatly reduce the excessive overhead. As such, failure prediction is critical in order to effectively utilize FT mechanisms. In addition, it also helps in system administration and management, as the predicted failure can be handled beforehand with limited impact to the running systems.
This dissertation proposes new proficiency metrics for failure prediction based on failure impact in UPC environment that the existing proficiency metrics tire unable to reflect. Furthermore, an efficient log message clustering algorithm is proposed for system event log data preprocessing and analysis. Then, two novel association rule mining approaches are introduced and employed for HPC failure prediction. Finally, the performances of the existing and the proposed association rule mining methods are compared and analyzed
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