Mahmoud Abo Khamis

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We present a simple geometric framework for the relational join. Using this framework, we design an algorithm that achieves the fractional hypertree-width bound, which generalizes classical and recent worst-case algorithmic results on computing joins. In addition, we use our framework and the same algorithm to show a series of what are colloquially known as(More)
Recently, Gottlob, Lee, Valiant, and Valiant (GLVV) presented an output size bound for join queries with functional dependencies (FD), based on a linear program on polymatroids. GLVV bound strictly generalizes the bound of Atserias, Grohe and Marx (AGM) for queries with no FD, in which case there are known algorithms running within the AGM-bound and thus(More)
Auditory-evoked potentials represent the response of the auditory pathway to an auditory stimulus. Specific language impairment (SLI) children have delayed language development with difficulties in both understanding and producing spoken language. Hence, the purpose of this study was to determine whether a group of children with SLI had abnormal changes in(More)
We consider list versions of sparse approximation problems, where unlike the existing results in sparse approximation that consider situations with unique solutions, we are interested in multiple solutions. We introduce these problems and present the first combinatorial results on the output list size. These generalize and enhance some of the existing(More)
BACKGROUND Chronic hepatitis C virus (HCV) infection is a globally serious public health issue. OBJECTIVES In this study, we investigated CC chemokine receptor 5 (CCR5-59029) polymorphism which is considered an important component of the immune system in determining the outcome of HCV infection. Its critical role as a marker in response to interferon(More)
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