We continue the study of approximating the number of distinct elements in the data stream model to within a (1 ± ) factor with constant probability. It was shown by Indyk and Woodruff (FOCS, 2003) that if the stream may consist of arbitrary data arriving to the streaming algorithm in an arbitrary order, then any 1-pass algorithm requires Ω(1/ ) bits of space to perform this task. In an attempt ...

A major goal in post-genome biology is the complete mapping of the gene regulatory networks for every organism. Identification of regulatory elements is a prerequisite for realizing this ambitious goal. A common problem is finding regulatory patterns in promoters of a group of co-expressed genes, but contemporary methods are challenged by the size and diversity of regulatory regions in higher m...

Any hereditarily finite set S can be represented as a finite pointed graph –dubbed membership graph– whose nodes denote elements of the transitive closure of {S} and whose edges model the membership relation. Membership graphs must be hyper-extensional –nodes are pairwise not bisimilar– and bisimilar nodes represent the same hereditarily finite set. It is worth to notice that the removal of eve...

knowledge is one of the most important accomplishments of human being in confrontation with phenomena and facts whichhe acquires through his cognitive faculties. throughout the history of philosophy, there was always this confusion that whether or not beliefs are influenced by his non-epistemic areas and external elements, and if so, is it epistemically acceptable or the agent should avoid thes...

Let S be a many sorted signature. A gate of S is an element of the operation symbols of S. Let A be a set and let f be a function. One can check that A 7−→ f is function yielding. Let f , g be non-empty functions. Observe that f +·g is non-empty. Let A, B be sets, let f be a many sorted set indexed by A, and let g be a many sorted set indexed by B. Then f +·g is a many sorted set indexed by A∪B...

We investigate a rst-order extension of the Theory of Primitive Objects of 5] that supports method extension in presence of object subsumption. Extension is the ability of modifying the behavior of an object by adding new methods (and inheriting the existing ones). Object subsumption allows to use objects with a bigger interface in a context expecting another object with a smaller interface. Th...