Showing papers by "Andrei Z. Broder published in 2001"
22 Apr 2001
TL;DR: This work describes an approach for obtaining good hash tables based on using multiple hashes of each input key (which is an IP address), which proves extremely suitable in instances where the goal is to have one hash bucket fit into a cache line.
Abstract: High performance Internet routers require a mechanism for very efficient IP address lookups. Some techniques used to this end, such as binary search on levels, need to construct quickly a good hash table for the appropriate IP prefixes. We describe an approach for obtaining good hash tables based on using multiple hashes of each input key (which is an IP address). The methods we describe are fast, simple, scalable, parallelizable, and flexible. In particular, in instances where the goal is to have one hash bucket fit into a cache line, using multiple hashes proves extremely suitable. We provide a general analysis of this hashing technique and specifically discuss its application to binary search on levels.
294 citations
Patent•
21 Sep 2001
TL;DR: A system and method for finding one or more target biometric samples that are similar to or match a query biometric sample is described in this paper. But the method does not address the problem of finding a set of features that are invariable or variable.
Abstract: A system and method for finding one or more target biometric samples that are similar to or match a query biometric sample. A query feature vector is generated from a query biometric vector. The query biometric vector represents the query biometric sample as a set of characteristics. The characteristics are either invariable or variable. The query feature vector comprises a plurality of features which are derived from the query biometric vector using a process that includes canonicalization of the characters in the biometric vector. The query feature vector is compared to a plurality of similarly created target feature vectors, each target feature vector representing a respective target biometric sample. A target biometric sample is a potential match to the query biometric sample when a threshold number of features in the corresponding target feature vector are identical to features in the query biometric vector.
68 citations
Patent•
25 May 2001TL;DR: In this article, a system and method are disclosed for selecting a resource, among a plurality of resources, for servicing a request, where a first resource is randomly selected and if a first load value associated with the first resource does not exceed a threshold value, the request is assigned to the first resources for servicing.
Abstract: A system and method are disclosed for selecting a resource, among a plurality of resources, for servicing a request. To select a resource to service the request, a first resource is randomly selected. If a first load value associated with the first resource does not exceed a threshold value, the request is assigned to the first resource for servicing. Otherwise a second resource is randomly selected. If a second load value associated with the second resource does not exceed a threshold value, the request is assigned to the second resource for servicing. If the second load value exceeds the threshold value, the request is assigned whichever of the first and second resources has a lower load value.
36 citations
TL;DR: In this article, the authors prove a sufficient condition for the stability of dynamic packet routing algorithms and show that certain high probability and worst case bounds on the quasi-static (finite past) performance of a routing algorithm imply bound on the performance of the dynamic version of that algorithm.
Abstract: We prove a sufficient condition for the stability of dynamic packet routing algorithms. Our approach reduces the problem of steady state analysis to the easier and better understood question of static routing. We show that certain high probability and worst case bounds on the quasi-static (finite past) performance of a routing algorithm imply bounds on the performance of the dynamic version of that algorithm. Our technique is particularly useful in analyzing routing on networks with bounded buffers where complicated dependices make standard queuing techniques inapplicable.We present several applications of our approach. In all cases we start from a known static algorithm, and modify it to fit our framework. In particular we give the first dynamic algorithms for routing on a butterfly or two-dimensional mesh with bounded buffers. Both the injection rate for which the algorithm is stable, and the expected time a packet spends in the system are optimal up to constant factors. Our approach is also applicable to the recently introduced adversarial input model.
13 citations
TL;DR: In this article, it was shown that any randomized sampling scheme for the relative intersection of sets based on testing equality of samples yields an equivalent min-wise independent family, and in a certain sense, minwise independent families are complete for this type of estimation.
Abstract: We provide several new results related to the concept of min-wise independence. Our main result is that any randomized sampling scheme for the relative intersection of sets based on testing equality of samples yields an equivalent min-wise independent family. Thus, in a certain sense, min-wise independent families are “complete” for this type of estimation.
6 citations