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Efficient Identification of Web Communities
 IN SIXTH ACM SIGKDD INTERNATIONAL CONFERENCE ON KNOWLEDGE DISCOVERY AND DATA MINING
, 2000
"... We define a community on the web as a set of sites that have more links (in either direction) to members of the community than to nonmembers. Members of such a community can be eciently identified in a maximum flow / minimum cut framework, where the source is composed of known members, and the sink ..."
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Cited by 289 (13 self)
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We define a community on the web as a set of sites that have more links (in either direction) to members of the community than to nonmembers. Members of such a community can be eciently identified in a maximum flow / minimum cut framework, where the source is composed of known members, and the sink consists of wellknown nonmembers. A focused crawler that crawls to a fixed depth can approximate community membership by augmenting the graph induced by the crawl with links to a virtual sink node. The effectiveness of the approximation algorithm is demonstrated with several crawl results that identify hubs, authorities, web rings, and other link topologies that are useful but not easily categorized. Applications of our approach include focused crawlers and search engines, automatic population of portal categories, and improved filtering.
A Tutorial on (Co)Algebras and (Co)Induction
 EATCS Bulletin
, 1997
"... . Algebraic structures which are generated by a collection of constructors like natural numbers (generated by a zero and a successor) or finite lists and trees are of wellestablished importance in computer science. Formally, they are initial algebras. Induction is used both as a definition pr ..."
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Cited by 269 (36 self)
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. Algebraic structures which are generated by a collection of constructors like natural numbers (generated by a zero and a successor) or finite lists and trees are of wellestablished importance in computer science. Formally, they are initial algebras. Induction is used both as a definition principle, and as a proof principle for such structures. But there are also important dual "coalgebraic" structures, which do not come equipped with constructor operations but with what are sometimes called "destructor" operations (also called observers, accessors, transition maps, or mutators). Spaces of infinite data (including, for example, infinite lists, and nonwellfounded sets) are generally of this kind. In general, dynamical systems with a hidden, blackbox state space, to which a user only has limited access via specified (observer or mutator) operations, are coalgebras of various kinds. Such coalgebraic systems are common in computer science. And "coinduction" is the appropriate te...
Cardinality of Set Partitions
, 2015
"... The theory’s main theorem states that the cardinality of set partitions of size k on a carrier set of size n is expressed by Stirling numbers of the second kind. In Isabelle, Stirling numbers of the second kind are defined in the AFP entry ‘Discrete Summation ’ [1] through their wellknown recurren ..."
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The theory’s main theorem states that the cardinality of set partitions of size k on a carrier set of size n is expressed by Stirling numbers of the second kind. In Isabelle, Stirling numbers of the second kind are defined in the AFP entry ‘Discrete Summation ’ [1] through their well
Maximum Cardinality Matching
, 2013
"... A matching in a graph G is a subset M of the edges of G such that no two share an endpoint. A matching has maximum cardinality if its cardinality is at least as large as that of any other matching. An oddset cover OSC of a graph G is a labeling of the nodes of G with integers such that every edge o ..."
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cardinality matching. We provide an Isabelle proof of Edmonds theorem. For an explanation
Keywords: gaze, adaptation, cardinal, noncardinal
"... Eye gaze is not coded by cardinal mechanisms alone ..."
Cardinals in Isabelle/HOL
"... Abstract. We report on a formalization of ordinals and cardinals in Isabelle/HOL. A main challenge we faced was the inability of higherorder logic to represent ordinals canonically, as transitive sets (as done in set theory). We resolved this into a “decentralized ” representation identifying ordin ..."
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Cited by 3 (2 self)
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Abstract. We report on a formalization of ordinals and cardinals in Isabelle/HOL. A main challenge we faced was the inability of higherorder logic to represent ordinals canonically, as transitive sets (as done in set theory). We resolved this into a “decentralized ” representation identifying
Decision Procedures for Multisets with Cardinality Constraints
"... Abstract. Applications in software verification and interactive theorem proving often involve reasoning about sets of objects. Cardinality constraints on such collections also arise in these applications. Multisets arise in these applications for analogous reasons as sets: abstracting the content of ..."
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Cited by 15 (8 self)
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Abstract. Applications in software verification and interactive theorem proving often involve reasoning about sets of objects. Cardinality constraints on such collections also arise in these applications. Multisets arise in these applications for analogous reasons as sets: abstracting the content
Decision Procedures for Multisets with Cardinality Constraints
"... The final statement of the paper (Corollary 1) remains unaffected. 1 Introduction Collections of objects are fundamental and ubiquitous concepts in computerscience and mathematics. It is therefore not surprising that they often arise in software analysis and verification [1], as well as in interacti ..."
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as in interactive theorem proving[19]. Moreover, such constraints often involve cardinality bounds on collections. Recent work describes decision procedures for constraints that involve sets andtheir cardinalities [10, 12], characterizing the complexity of both quantified and quantifierfree constraints.In many
WS1S with Cardinality Constraints
, 2001
"... The weak monadic secondorder logic of one successor, WS1S, is an expressive logic known to be decidable. Many interesting problems, however, fall outside the scope of this logic. We extend WS1S with cardinality constraints. As an example, we show that the Petri net reachability problem can be expre ..."
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Cited by 1 (0 self)
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The weak monadic secondorder logic of one successor, WS1S, is an expressive logic known to be decidable. Many interesting problems, however, fall outside the scope of this logic. We extend WS1S with cardinality constraints. As an example, we show that the Petri net reachability problem can
Results 1  10
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2,841