Learn More
In practice, almost all dynamic systems require decisions to be made online, without full knowledge of their future impact on the system. We introduce a general model for the processing of sequences of tasks and develop a general online decision algorithm. We show that, for an important class of special cases, this algorithm is optimal among all online(More)
Recently, there have been a number of algorithms proposed for analyzing hypertext link structure so as to determine the best " authorities " for a given topic or query. While such analysis is usually combined with content analysis, there is a sense in which some algorithms are deemed to be " more balanced " and others " more focused ". We undertake a(More)
We consider packet routing when packets are injected continuously into a network. We develop an adversarial theory of queueing aimed at addressing some of the restrictions inherent in probabilistic analysis and queueing theory based on stochastic generation. Our approach sheds light on various queueing policies in simple networks, and paves the way for the(More)
In practice, almost all dynamic systems require decisions to be made on-line, without full knowledge of their future impact on the system. A general model for the processing of sequences of tasks is introduced, and a general on-line decision algorithm is developed. It is shown that, for an important class of special cases, this algorithm is optimal among(More)
The explosive growth and the widespread accessibility of the Web has led to a surge of research activity in the area of information retrieval on the World Wide Web. The seminal papers of Kleinberg [1998, 1999] and Brin and Page [1998] introduced <i>Link Analysis Ranking</i>, where hyperlink structures are used to determine the relative <i>authority</i> of a(More)
A syntactic read-k-times branching program has the restriction that no variable occurs more than k times on any path (whether or not consistent) of the branching program. We first extend the result in [31], to show that the "n/2 clique only function", which is easily seen to be computable by deterministic polynomial size read-twice programs , cannot be(More)
We consider packet routing when packets are injected continuously into a network. We develop an adversarial theory of queuing aimed at addressing some of the restrictions inherent in probabilistic analysis and queuing theory based on time-invariant stochastic generation. We examine the stability of queuing networks and policies when the arrival process is(More)
It is shown that a probabilistic Turing acceptor or transducer running within space bound S can be simulated by a time S 2 parallel machine and therefore by a space S 2 deterministic machine. (Previous simulations ran in space $6.) In order to achieve these simulations, known algorithms are extended for the computation of determinants in small arithmetic(More)