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On the Relative Complexity of Resolution Refinements and Cutting Planes Proof Systems
, 2000
"... An exponential lower bound for the size of treelike Cutting Planes refutations of a certain family of CNF formulas with polynomial size resolution refutations is proved. This implies an exponential separation between the treelike versions and the daglike versions of resolution and Cutting Planes. ..."
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Cited by 40 (9 self)
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An exponential lower bound for the size of treelike Cutting Planes refutations of a certain family of CNF formulas with polynomial size resolution refutations is proved. This implies an exponential separation between the treelike versions and the daglike versions of resolution and Cutting Planes. In both cases only superpolynomial separations were known [29, 18, 8]. In order to prove these separations, the lower bounds on the depth of monotone circuits of Raz and McKenzie in [25] are extended to monotone real circuits. An exponential separation is also proved between treelike resolution and several refinements of resolution: negative resolution and regular resolution. Actually this last separation also provides a separation between treelike resolution and ordered resolution, thus the corresponding superpolynomial separation of [29] is extended. Finally, an exponential separation between ordered resolution and unrestricted resolution (also negative resolution) is proved. Only a superpolynomial separation between ordered and unrestricted resolution was previously known [13].
Exponential Separations between Restricted Resolution and Cutting Planes Proof Systems
, 1998
"... We prove an exponential lower bound for treelike Cutting Planes refutations of a set of clauses which has polynomial size resolution refutations. This implies an exponential separation between treelike and daglike proofs for both CuttingPlanes and resolution; in both cases only superpolynomial se ..."
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Cited by 28 (5 self)
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We prove an exponential lower bound for treelike Cutting Planes refutations of a set of clauses which has polynomial size resolution refutations. This implies an exponential separation between treelike and daglike proofs for both CuttingPlanes and resolution; in both cases only superpolynomial separations were known before [30, 20, 10]. In order to prove this, we extend the lower bounds on the depth of monotone circuits of Raz and McKenzie [26] to monotone real circuits. In the case of resolution, we further improve this result by giving an exponential separation of treelike resolution from (daglike) regular resolution proofs. In fact, the refutation provided to give the upper bound respects the stronger restriction of being a DavisPutnam resolution proof. This extends the corresponding superpolynomial separation of [30]. Finally, we prove an exponential separation between DavisPutnam resolution and unrestricted resolution proofs; only a superpolynomial separation was previously...
JAMRESISTANT COMMUNICATION WITHOUT SHARED SECRETS THROUGH THE USE OF CONCURRENT CODES
, 2007
"... We consider the problem of establishing jamresistant, wireless, omnidirectional communication channels when there is no initial shared secret. No existing system achieves this. We propose a general algorithm for this problem, the BBC algorithm, and give several instantiations of it. We develop an ..."
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Cited by 17 (9 self)
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We consider the problem of establishing jamresistant, wireless, omnidirectional communication channels when there is no initial shared secret. No existing system achieves this. We propose a general algorithm for this problem, the BBC algorithm, and give several instantiations of it. We develop and analyze this algorithm within the framework of a new type of code, concurrent codes, which are those superimposed codes that allow efficient decoding. Finally, we propose the Universal Concurrent Code algorithm, and prove that it covers all possible concurrent codes, and give connections between its theory and that of monotone Boolean functions.
Jam resistant communications without shared secrets
 in Proceedings of the 3 rd International Conference on Information Warfare and Security
, 2008
"... Distribution A, Approved for public release, distribution unlimited Abstract. We consider the problem of establishing jamresistant, wireless, omnidirectional communication channels when there is no initial shared secret. No existing system achieves this. We propose a general algorithm for this prob ..."
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Cited by 10 (1 self)
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Distribution A, Approved for public release, distribution unlimited Abstract. We consider the problem of establishing jamresistant, wireless, omnidirectional communication channels when there is no initial shared secret. No existing system achieves this. We propose a general algorithm for this problem, the BBC algorithm, and give several instantiations of it. We develop and analyze this algorithm within the framework of a new type of code, concurrent codes, which are those superimposed codes that allow efficient decoding. Finally, we propose the Universal Concurrent Code algorithm, and prove that it covers all possible concurrent codes, and give connections between its theory and that of monotone Boolean functions.
Exponential Separations between Restricted Resolution and Cutting Planes Proof Systems
, 1998
"... We prove an exponential lower bound for treelike Cutting Planes refutations of a set of clauses which has polynomial size resolution refutations. This implies an exponential separation between treelike and daglike proofs for both CuttingPlanes and resolution; in both cases only superpolynomial se ..."
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We prove an exponential lower bound for treelike Cutting Planes refutations of a set of clauses which has polynomial size resolution refutations. This implies an exponential separation between treelike and daglike proofs for both CuttingPlanes and resolution; in both cases only superpolynomial separations were known before [30, 20, 10]. In order to prove this, we extend the lower bounds on the depth of monotone circuits of Raz and McKenzie [26] to monotone real circuits. In the case of resolution, we further improve this result by giving an exponential separation of treelike resolution from (daglike) regular resolution proofs. In fact, the refutation provided to give the upper bound respects the stronger restriction of being a DavisPutnam resolution proof. This extends the corresponding superpolynomial separation of [30]. Finally, we prove an exponential separation between DavisPutnam resolution and unrestricted resolution proofs; only a superpolynomial separation was previously...
On the Relative Complexity of Resolution Refinements and Cutting Planes Proof Systems*
"... Abstract An exponential lower bound for the size of treelike Cutting Planes refutations of a certainfamily of CN F formulas with polynomial size resolution refutations is proved. This impliesan exponential separation between the treelike versions and the daglike versions of resolution ..."
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Abstract An exponential lower bound for the size of treelike Cutting Planes refutations of a certainfamily of CN F formulas with polynomial size resolution refutations is proved. This impliesan exponential separation between the treelike versions and the daglike versions of resolution