Mohan Yang

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An increasing number of applications operate on data obtained from the Web. These applications typically maintain local copies of the web data to avoid network latency in data accesses. As the data on the Web evolves, it is critical that the local copy be kept up-to-date. Data freshness is one of the most important data quality issues, and has been(More)
Data uncertainty arises in many situations. A common approach to query processing uncertain data is to sample many "possible worlds" from the uncertain data and to run queries against the possible worlds. However, sampling is not a trivial task, as a randomly sampled possible world may not satisfy known constraints imposed on the data. In this paper, we(More)
Supporting iteration and/or recursion for advanced big data analytics requires reexamination of classical algorithms on modern computing environments. Several recent studies have focused on the implementation of transitive closure in multi-node clusters. Algorithms that deliver optimal performance on multi-node clusters are hardly optimal on multicore(More)
There is great interest in exploiting the opportunity provided by cloud computing platforms for large-scale analytics. Among these platforms, Apache Spark is growing in popularity for machine learning and graph analytics. Developing efficient complex analytics in Spark requires deep understanding of both the algorithm at hand and the Spark API or subsystem(More)
We aim to provide table answers to keyword queries using a knowledge base. For queries referring to multiple entities, like " Wash-ington cities population " and " Mel Gibson movies " , it is better to represent each relevant answer as a table which aggregates a set of entities or joins of entities within the same table scheme or pattern. In this paper, we(More)
Delivering superior expressive power over RDBMS, while maintaining competitive performance , has represented the main goal and technical challenge for deductive database research since its inception forty years ago. Significant progress toward this ambitious goal is being achieved by the DeALS system through the parallel bottom-up evaluation of logic(More)
The exploding demand for analytics has refocused the attention of data scientists on applications requiring aggregation in recursion. After resisting the efforts of researchers for more than twenty years, this problem is being addressed by innovative systems that are raising logic-oriented data languages to the levels of generality and performance that are(More)
—Higher order differential cryptanalysis is based on the property of higher order derivatives of Boolean functions that the degree of a Boolean function can be reduced by at least 1 by taking a derivative on the function at any point. We define fast point as the point at which the degree can be reduced by at least 2. In this paper, we show that the fast(More)
There is much current interest in applications of complex event processing over data streams and of complex pattern matching over stored sequences. While some applications use streams of flat records, XML and various semi-structured information formats are preferred by many others-in particular, applications that deal with domain science, social networks,(More)