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863
Look-back Techniques for ASP Programs with Aggregates
"... One of the most significant language extensions to Answer Set Programming (ASP) has been the introduction of aggregates. A significant amount of theoretical and practical work on aggregates in ASP has been published in recent years. In spite of these developments, aggregates are treated in a quite s ..."
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Cited by 2 (1 self)
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straightforward and ad-hoc way in most ASP systems. For the system DLV, several specialized techniques for aggregates have been described in [6], however still leaving a lot of room for improvement. In this paper, we build upon work on look-back optimization techniques done recently for DLV, and extend its reason
IOS Press Look-back Techniques for ASP Programs with Aggregates ∗
"... Abstract. The introduction of aggregates has been one of the most relevant language extensions to Answer Set Programming (ASP). Aggregates are very expressive, they allow to represent many problems in a more succinct and elegant way compared to aggregate-free programs. A significant amount of resear ..."
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techniques for an efficient implementation of aggregates. We define a reason calculus for backjumping in ASP programs with aggregates. Furthermore, we describe how these reasons can be used in order to guide look-back heuristics for programs with aggregates. We have implemented both the new reason calculus
Data cube: A relational aggregation operator generalizing group-by, cross-tab, and sub-totals
, 1996
"... Abstract. Data analysis applications typically aggregate data across many dimensions looking for anomalies or unusual patterns. The SQL aggregate functions and the GROUP BY operator produce zero-dimensional or one-dimensional aggregates. Applications need the N-dimensional generalization of these op ..."
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Cited by 860 (11 self)
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Abstract. Data analysis applications typically aggregate data across many dimensions looking for anomalies or unusual patterns. The SQL aggregate functions and the GROUP BY operator produce zero-dimensional or one-dimensional aggregates. Applications need the N-dimensional generalization
Look-Back Techniques and Heuristics in DLV: Implementation and Evaluation ⋆
"... Abstract. Answer Set Programming (ASP) is a purely-declarative programming paradigm based on logic rules, allowing for both disjunction in the head of the rules and nonmonotonic negation in the body. ASP can express any property whose complexity is in the second level of the polynomial hierarchy, t ..."
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recently, DLV did not incorporate any "backjumping" techniques (neither did other disjunctive ASP systems). Related, DLV could not use "look-back" information accumulated for backjumping in its heuristics, which have been shown in related research areas to be crucial on large benchmarks
The Determinants of Credit Spread Changes.
- Journal of Finance
, 2001
"... ABSTRACT Using dealer's quotes and transactions prices on straight industrial bonds, we investigate the determinants of credit spread changes. Variables that should in theory determine credit spread changes have rather limited explanatory power. Further, the residuals from this regression are ..."
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Cited by 422 (2 self)
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, and Southern Methodist University. The relation between stock and bond returns has been widely studied at the aggregate level (see, for example, Campbell and Ammer (1993), Keim and Stambaugh (1986), Fama and French (1989), and Fama and French (1993)). Recently, a few studies have investigated that relation
Experimenting with look-back heuristics for hard ASP programs
- Proceedings of the Ninth International Conference on Logic Programming and Nonmonotonic Reasoning (LPNMR’07
, 2007
"... Abstract. Competitive native solvers for Answer Set Programming (ASP) perform a backtracking search by assuming the truth of literals. The choice of literals (the heuristic) is fundamental for the performance of these systems. Most of the efficient ASP systems employ a heuristic based on look-ahead ..."
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Cited by 2 (1 self)
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this approach to the framework of disjunctive ASP. We design a number of look-back heuristics exploiting peculiarities of ASP and implement them in the ASP system DLV. We compare their performance on a collection of hard ASP programs both structured and randomly generated. These experiments indicate that a very
Interpreting the data: Parallel analysis with Sawzall.
- Scientific Programming Journal,
, 2005
"... Abstract Very large data sets often have a flat but regular structure and span multiple disks and machines. Examples include telephone call records, network logs, and web document repositories. These large data sets are not amenable to study using traditional database techniques, if only because th ..."
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Cited by 273 (0 self)
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, in which a query is expressed using a new procedural programming language, emits data to an aggregation phase. Both phases are distributed over hundreds or even thousands of computers. The results are then collated and saved to a file. The design -including the separation into two phases, the form
Conflict-driven answer set solving
- in Proceedings IJCAI’07
, 2007
"... We introduce a new approach to computing answer sets of logic programs, based on concepts from constraint processing (CSP) and satisfiability checking (SAT). The idea is to view inferences in answer set programming (ASP) as unit propagation on nogoods. This provides us with a uniform constraintbased ..."
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Cited by 201 (48 self)
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We introduce a new approach to computing answer sets of logic programs, based on concepts from constraint processing (CSP) and satisfiability checking (SAT). The idea is to view inferences in answer set programming (ASP) as unit propagation on nogoods. This provides us with a uniform
Stochastic Dynamic Programming with Factored Representations
, 1997
"... Markov decision processes(MDPs) have proven to be popular models for decision-theoretic planning, but standard dynamic programming algorithms for solving MDPs rely on explicit, state-based specifications and computations. To alleviate the combinatorial problems associated with such methods, we pro-p ..."
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Cited by 189 (10 self)
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decision-tree representation of rewards. Based on this representation, we develop versions of standard dynamic programming algorithms that directly manipulate decision-tree representations of policies and value functions. This generally obviates the need for state-by-state computation, aggregating states
Recursive Aggregates in Disjunctive Logic Programs: Semantics and Complexity
- In Proceedings of European Conference on Logics in Artificial Intelligence (JELIA
, 2004
"... Abstract. The addition of aggregates has been one of the most relevant enhancements to the language of answer set programming (ASP). They strengthen the modeling power of ASP, in terms of concise problem representations. While many important problems can be encoded using nonrecursive aggregates, som ..."
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Cited by 115 (15 self)
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Abstract. The addition of aggregates has been one of the most relevant enhancements to the language of answer set programming (ASP). They strengthen the modeling power of ASP, in terms of concise problem representations. While many important problems can be encoded using nonrecursive aggregates
Results 1 - 10
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863