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Alejandro López-Ortiz
Researcher at University of Waterloo
Publications - 198
Citations - 3856
Alejandro López-Ortiz is an academic researcher from University of Waterloo. The author has contributed to research in topics: Competitive analysis & List update problem. The author has an hindex of 33, co-authored 193 publications receiving 3719 citations. Previous affiliations of Alejandro López-Ortiz include Open Text Corporation & University of New Brunswick.
Papers
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Book ChapterDOI
Frequency Estimation of Internet Packet Streams with Limited Space
TL;DR: In this article, the authors consider a router on the Internet analyzing the statistical properties of a TCP/IP packet stream and present an algorithm that deterministically finds (in particular) all categories having a frequency above 1/(m+1) using m counters, which is best possible in the worst case.
Proceedings ArticleDOI
Adaptive set intersections, unions, and differences
TL;DR: This work develops a framework for designing and evaluating adaptive algorithms in the comparison model, and presents adaptive algorithms that make no a priori assumptions about the problem instance, and show that their running times are within a constant factor of optimal with respect to a natural measure of the difficulty of an instance.
Proceedings ArticleDOI
Identifying frequent items in sliding windows over on-line packet streams
TL;DR: This paper presents a deterministic algorithm for identifying frequent items in sliding windows defined over real-time packet streams that uses limited memory, requires constant processing time per packet, makes only one pass over the data, and is shown to work well when tested on TCP traffic logs.
Proceedings ArticleDOI
On the number of distributed measurement points for network tomography
TL;DR: In this article, the minimum number of required beacons on a network under a BGP-like routing policy is shown to be NP-hard and at best Ω(log n)-approximable.
Book ChapterDOI
Faster adaptive set intersections for text searching
TL;DR: A better algorithm for the intersection of large ordered sets is engineer, which improves over those proposed by Demaine, Munro and Lopez-Ortiz [SODA 2000/ALENEX 2001], by using a variant of interpolation search.