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Showing papers in "Journal of Computer and System Sciences in 2007"


Journal ArticleDOI
TL;DR: A new method for handling multicriteria fuzzy decision-making problems based on intuitionistic fuzzy sets is presented and can provide a useful way to efficiently help the decision-maker to make his decision.

329 citations


Journal ArticleDOI
TL;DR: An overview of fundamental properties of the different kinds of automata used in XML processing are given to relate them to the four key aspects of XML processing: schemas, navigation, querying and transformation.

154 citations


Journal ArticleDOI
TL;DR: In this article, it was shown that every scoring-protocol election system having two or more point values assigned to candidates other than the favorite is NP-complete to manipulate, i.e., having @?{@a"i|2|2==2-is a voting system that cannot be manipulated in polynomial time.

127 citations


Journal ArticleDOI
TL;DR: An algorithm is given that computes the consistent answers for a large and practical class of conjunctive queries by returning a first-order query Q such that for every (potentially inconsistent) database I, the consistent answer can be obtained by evaluating Q directly on I.

123 citations


Journal ArticleDOI
TL;DR: Data-driven Web applications provided by Web sites interacting with users or applications, and the results establish under what conditions automatic verification of such properties is possible and provide the complexity of verification are studied.

121 citations


Journal ArticleDOI
TL;DR: A novel information-theoretic standard for query-view security is presented, which can be used to provide a precise analysis of information disclosure for a host of data exchange scenarios, including multi-party collusion and the use of outside knowledge by an adversary trying to learn privileged facts about the database.

100 citations


Journal ArticleDOI
TL;DR: It is proved that when preemption is allowed, Shortest Remaining Processing Time (SRPT) is an O(log(min{nm,P})) approximation algorithm for the total flow time, and it is shown that up to a constant factor SRPT is an optimal on-line algorithm.

90 citations


Journal ArticleDOI
TL;DR: It is shown that confluent P systems with active membranes solve in polynomial time exactly the class of problems PSPACE, suggesting that the class PSPACE provides a tight upper bound on the computational potential of biological information processing models.

88 citations


Journal ArticleDOI
TL;DR: The results show that the capabilities provided by PICML - combined with its design and deployment-time validation capabilities - eliminates many common errors associated with conventional techniques, thereby increasing the effectiveness of applying QoS-enabled component middleware technologies to the DRE system domain.

86 citations


Journal ArticleDOI
TL;DR: This work shows that the class of one-pass preorder typeable schemas allows for polynomial time minimization and unique minimal models and investigates abstractions of XML schema languages.

81 citations


Journal ArticleDOI
TL;DR: Several well-known artificial life techniques are studied to gauge their suitability for solving grid load balancing problems and the effectiveness of each algorithm is shown for a number of test problems, especially when prediction information is not fully accurate.

Journal ArticleDOI
TL;DR: The inapproximability results for a given dfa with n states are based on cryptographic assumptions and it is shown that any efficient algorithm will have an approximation factor of at least npoly(logn).

Journal ArticleDOI
TL;DR: A new deterministic paging algorithm is devised, Retrospective-LRU, and it is found that LRU is better than FWF, and look-ahead is shown to be a significant advantage, in contrast to the competitive ratio, which does not reflect that look- Ahead can be helpful.

Journal ArticleDOI
TL;DR: It is proved that for countable scattered linear orderings, the two notions of finite automata and rational expressions are equivalent, which extends Kleene's theorem.

Journal ArticleDOI
TL;DR: The ability to compute XML key propagation is a first step toward establishing a connection between XML data and its relational representation at the semantic level.

Journal ArticleDOI
TL;DR: The property that the order finding algorithm works for any group is used to design a simple O(n) algorithm for testing whether a group of size n, described by its multiplication table, is nilpotent and an algorithm for isomorphism testing of Abelian groups is given.

Journal ArticleDOI
TL;DR: This work investigates how much redundancy 3NF tolerates in order to achieve dependency preservation and provides a characterization of cases when an XML normal form called XNF guarantees both redundancy elimination and dependency preservation by a hierarchical representation of relational data in XML.

Journal ArticleDOI
TL;DR: A fuzzy closure operator is described the fixed points of which are just clusters which uniquely determine the blocks of clusters of the factor lattice that represents an approximate version of the original concept lattice.

Journal ArticleDOI
TL;DR: A generic synchronization framework is implemented that can be used to build state-based synchronizers for a wide variety of tree-structured data formats, and a novel feature of this framework is that the synchronization process, in particular, the recognition of conflicts-is driven by the schema of the structures being synchronized.

Journal ArticleDOI
TL;DR: This paper presents a general lower bound technique, which given a query, specifies the minimum amount of memory that any algorithm evaluating the query on a stream would need to incur, and states the lower bounds in terms of new graph-theoretic properties of queries.

Journal ArticleDOI
TL;DR: This work proposes a generalization of the well-known Magic Sets technique to Datalog^@?

Journal ArticleDOI
TL;DR: The notion of spatially-decaying aggregation is formalized and efficient algorithms for fundamental aggregation functions, including sums and averages, random sampling, heavy hitters, quantiles, and L"p norms are developed.

Journal ArticleDOI
TL;DR: Moran and Snir as mentioned in this paper presented a 2-approximation algorithm for the problem of convex recoloring of strings with running time O(cn), where c is the number of colors and n is the size of the input.

Journal ArticleDOI
TL;DR: This paper presents a dynamic and decentralized load balancing algorithm for computationally intensive jobs on a heterogeneous distributed computing platform and shows that the proposed algorithm outperforms conventional approaches over a wide range of system parameters.

Journal ArticleDOI
TL;DR: Light is shed on when to use fast complete algorithms and when to reside to sound but incomplete ones on typechecking, as it is shown that most scenarios cannot be enlarged without rendering the typechecking problem intractable.

Journal ArticleDOI
TL;DR: A new property for graphs along with an associated graph class (a generalization on bounded degree graphs) is introduced and the known classes of inputs for which polynomial-time subgraph isomorphism algorithms are attainable are extended.

Journal ArticleDOI
TL;DR: It is proved that computing hit probability of a spaced seed in a uniform homology region is NP-hard, but it admits a probabilistic PTAS, and it is shown that the asymptotic hit probability is computable in exponential time in seed length, independent of the homologous region length.

Journal ArticleDOI
TL;DR: This paper presents a class of algorithms that guarantee validity in dynamic networks, and specifies a correctness condition, Single-Site Validity, with respect to which the above algorithms are best-effort.

Journal ArticleDOI
TL;DR: In this paper, it was shown that the class S"2p is contained in ZPP^N^P. The proof uses universal hashing, approximate counting and witness sampling, which is the strongest version to date of the Karp-Lipton Theorem.

Journal ArticleDOI
TL;DR: These results solve several of the open questions raised by Buhrman and Torenvliet in their 1994 survey paper on the structure of complete sets.