Results 1  10
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215
Loopy belief propagation for approximate inference: An empirical study. In:
 Proceedings of Uncertainty in AI,
, 1999
"... Abstract Recently, researchers have demonstrated that "loopy belief propagation" the use of Pearl's polytree algorithm in a Bayesian network with loops can perform well in the context of errorcorrecting codes. The most dramatic instance of this is the near Shannonlimit performanc ..."
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Cited by 676 (15 self)
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to the correct marginals. However, on the QMR network, the loopy be liefs oscillated and had no obvious relation ship to the correct posteriors. We present some initial investigations into the cause of these oscillations, and show that some sim ple methods of preventing them lead to the wrong results
On the (im)possibility of obfuscating programs
 Lecture Notes in Computer Science
, 2001
"... Informally, an obfuscator O is an (efficient, probabilistic) “compiler ” that takes as input a program (or circuit) P and produces a new program O(P) that has the same functionality as P yet is “unintelligible ” in some sense. Obfuscators, if they exist, would have a wide variety of cryptographic an ..."
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Cited by 348 (24 self)
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and complexitytheoretic applications, ranging from software protection to homomorphic encryption to complexitytheoretic analogues of Rice’s theorem. Most of these applications are based on an interpretation of the “unintelligibility ” condition in obfuscation as meaning that O(P) is a “virtual black box
Complexes of graph homomorphisms
 Israel J. Math
"... Abstract. Hom (G, H) is a polyhedral complex defined for any two undirected graphs G and H. This construction was introduced by Lovász to give lower bounds for chromatic numbers of graphs. In this paper we initiate the study of the topological properties of this class of complexes. We prove that Hom ..."
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Cited by 48 (10 self)
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Abstract. Hom (G, H) is a polyhedral complex defined for any two undirected graphs G and H. This construction was introduced by Lovász to give lower bounds for chromatic numbers of graphs. In this paper we initiate the study of the topological properties of this class of complexes. We prove
The Descriptive Complexity of Parity Games
, 2008
"... We study the logical definablity of the winning regions of parity games. For games with a bounded number of priorities, it is wellknown that the winning regions are definable in the modal µcalculus. Here we investigate the case of an unbounded number of priorities, both for finite game graphs and ..."
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Cited by 5 (4 self)
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We study the logical definablity of the winning regions of parity games. For games with a bounded number of priorities, it is wellknown that the winning regions are definable in the modal µcalculus. Here we investigate the case of an unbounded number of priorities, both for finite game graphs
Data Exchange: Getting to the Core
, 2003
"... Data exchange is the problem of taking data structured under a source schema and creating an instance of a target schema that reflects the source data as accurately as possible. Given a source instance, there may be many solutions to the data exchange problem, that is, many target instances that sat ..."
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Cited by 168 (19 self)
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this, we investigate the computational complexity of producing the core. Wellknown results by Chandra and Merlin imply that, unless P = NP, there is no polynomialtime algorithm that, given a structure as input, returns the core of that structure as output. In contrast, in the context of data e...
The Homomorphism Domination Exponent
, 2009
"... We initiate a study of the homomorphism domination exponent of a pair of graphs F and G, defined as the maximum real number c such that Hom(F, T)  � Hom(G, T)  c for every graph T. The problem of determining whether HDE(F, G) � 1 is known as the homomorphism domination problem and its decidabi ..."
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Cited by 6 (0 self)
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We initiate a study of the homomorphism domination exponent of a pair of graphs F and G, defined as the maximum real number c such that Hom(F, T)  � Hom(G, T)  c for every graph T. The problem of determining whether HDE(F, G) � 1 is known as the homomorphism domination problem and its
Counting list homomorphisms and graphs with bounded degrees
, 2003
"... In a series of papers we have classified the complexity of list homomorphism problems.Here we investigate the effect of restricting the degrees of the input graphs. It turns out that the complexity does not change (except when the degree bound is two). We obtain similarresults on restricting the si ..."
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In a series of papers we have classified the complexity of list homomorphism problems.Here we investigate the effect of restricting the degrees of the input graphs. It turns out that the complexity does not change (except when the degree bound is two). We obtain similarresults on restricting
Graph Searching, Parity Games and Imperfect Information
"... We investigate the interrelation between graph searching games and games with imperfect information. As key consequence we obtain that parity games with bounded imperfect information can be solved in Ptime on graphs of bounded DAGwidth which generalizes several results for parity games on graphs o ..."
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Cited by 1 (1 self)
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We investigate the interrelation between graph searching games and games with imperfect information. As key consequence we obtain that parity games with bounded imperfect information can be solved in Ptime on graphs of bounded DAGwidth which generalizes several results for parity games on graphs
The Complexity of Symmetric Boolean Parity Holant Problems (Extended Abstract)
"... Abstract. For certain subclasses of NP, ⊕P or #P characterized by local constraints, it is known that if there exist any problems that are not polynomial time computable within that subclass, then those problems are NP, ⊕P or #Pcomplete. Such dichotomy results have been proved for characterizatio ..."
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Cited by 12 (3 self)
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for characterizations such as Constraint Satisfaction Problems, and directed and undirected Graph Homomorphism Problems, often with additional restrictions. Here we give a dichotomy result for the more expressive framework of Holant Problems. These additionally allow for the expression of matching problems, which have
On decoding of lowdensity paritycheck codes over the binary erasure channel
 IEEE Trans. Inform. Theory
, 2004
"... Abstract—This paper investigates decoding of lowdensity paritycheck (LDPC) codes over the binary erasure channel (BEC). We study the iterative and maximumlikelihood (ML) decoding of LDPC codes on this channel. We derive bounds on the ML decoding of LDPC codes on the BEC. We then present an improv ..."
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Cited by 30 (0 self)
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Abstract—This paper investigates decoding of lowdensity paritycheck (LDPC) codes over the binary erasure channel (BEC). We study the iterative and maximumlikelihood (ML) decoding of LDPC codes on this channel. We derive bounds on the ML decoding of LDPC codes on the BEC. We then present
Results 1  10
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215