# Omer Berkman

• J. Algorithms
• 1993
The all nearest smaller values problem is deened as follows. Let A = (a 1 ; a 2 ; : : :; a n) be n elements drawn from a totally ordered domain. For each a i , 1 i n, nd the two nearest elements in A that are smaller than a i (if such exist): the left nearest smaller element a j (with j < i) and the right nearest smaller element a k (with k > i). We give an(More)
• Proceedings of the National Academy of Sciences…
• 2005
Predicting the metabolic state of an organism after a gene knockout is a challenging task, because the regulatory system governs a series of transient metabolic changes that converge to a steady-state condition. Regulatory on/off minimization (ROOM) is a constraint-based algorithm for predicting the metabolic steady state after gene knockouts. It aims to(More)
• J. Comput. Syst. Sci.
• 1994
The level-ancestor problem is considered. Suppose a rooted tree T is given for preprocessing. Answer quickly queries of the following form. Given a vertex v and an integer i > 0, find the ith vertex on the path from v to the root. Given any m, 1 ~<m~<log* n, we achieve the following results: (1) O(log (m) n) a time using an optimal number of processors for(More)
• SIAM J. Comput.
• 2000
The notion of t rai tor tracing was introduced by Chor, Fiat and Naor, in order to combat piracy scenarios. Recently, Fiat and Tassa proposed a dynamic traitor tracing scenario, in which the algorithm adapts dynamically according to the responses of the pirate. Let n be the number of users and p the number of traitors. Our main result is an algorithm which(More)
• Financial Cryptography
• 2007
We describe new attacks on the financial PIN processing API. The attacks apply to switches as well as to verification facilities. The attacks are extremely severe allowing an attacker to expose customer PINs by executing only one or two API calls per exposed PIN. One of the attacks uses only the translate function which is a required function in every(More)
• STOC
• 1989
of Results. We establish that several problems are highly parallelizable. For each of these problems, we design an optimal 0 (loglogn ) time parallel algorithm on the Common CRCW PRAM model which is the weakest among the CRCW PRAM models. These problems include: 0 all nearest smaller values, l preprocessing for answering range maxima queries, l several(More)
• J. Algorithms
• 1998
We consider the problem of computing the minimumof n values and several well known generalizations pre x minima range minima and all nearest smaller values or ansv for input elements drawn from the integer domain s where s n In this paper we give simple and e cient algorithms for all of the above problems These algorithms all take O log log log s time using(More)