Mohamed A. Sharaf

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This paper presents TiNA, a scheme for minimizing energy consumption in sensor networks by exploiting end-user tolerance to temporal coherency. TiNA utilizes temporal coherency tolerances to both reduce the amount of information transmitted by individual nodes (communication cost dominates power usage in sensor networks), and to improve quality of data when(More)
In-network aggregation has been proposed as one method for reducing energy consumption in sensor networks. In this paper, we explore two ideas related to further reducing energy consumption in the context of in-network aggregation. The first is by influencing the construction of the routing trees for sensor networks with the goal of reducing the size of(More)
In-network aggregation has been proposed as one method for reducing energy consumption in networked sensors. In this paper, we explore the idea of influencing the construction of the routing trees for sensor networks with the goal of reducing the size of transmitted data for networks with in-network aggregation involving Group By queries. Toward this, we(More)
Minimizing energy consumption has been a major objective at all levels in sensor networks. In this paper, we present TiNA, an in-network aggregation scheme that maintains the user-specified quality of data requirement while significantly reducing the overall energy consumption. Specifically, since communication dominates power usage in sensor networks, TiNA(More)
Data Stream Management Systems are being developed to process continuous queries over multiple data streams. These continuous queries are typically used for monitoring purposes where the detection of an event might trigger a sequence of actions or the execution of a set of specified tasks. Such events are identified by tuples produced by a query and hence,(More)
Aggregate Continuous Queries (ACQs) are both a very popular class of Continuous Queries (CQs) and also have a potentially high execution cost. As such, optimizing the processing of ACQs is imperative for Data Stream Management Systems (DSMSs) to reach their full potential in supporting (critical) monitoring applications. For multiple ACQs that vary in(More)
A major problem on the Internet is the scalable dissemination of information. This problem is particularly acute exactly at the time when the scalability of data delivery is most important, e.g., election results on the night of the 2000 United States presidential election, and news during 9/11/2001. The current unicast pull framework simply does not scale(More)
Nowadays Electronic Health Records (EHRs) is a preferred method to store patients' health records. The emergence of cloud computing services provides users with flexible access, large storage capability and low costs, which motivate EHR maintainers to consider migrating EHR data from their own storage to the cloud. However, securing EHRs in cloud is a major(More)
In highly interactive dynamic web database systems, user satisfaction determines their success. In such systems, user requested web pages are dynamically created by executing a number of database queries or web transactions. In this paper, we model the interrelated transactions generating a web page as workflows and quantify the user satisfaction by(More)