In Multi-Agent Systems, Organizations are means to structure cooperation and collaboration between agents. MoiseInst is a normative Organization model giving the possibility to constraint agents behaviour according to...
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ISBN:
(纸本)9783642177217
In Multi-Agent Systems, Organizations are means to structure cooperation and collaboration between agents. MoiseInst is a normative Organization model giving the possibility to constraint agents behaviour according to four dimensions (structural, functional, contextual and normative). Mabeli as Electronic Institution model allows the supervision of MoiseInst Organizations compliance through an arbitration system. The difficulty is to easily instantiate such Organizations to obtain a dynamic entity in which agents can evolve. In this paper we introduce Utopia, our Institution-oriented and Institution-based programming framework. Utopia permits to easily and automatically set up a MAS thanks to a XML MoiseInst Specification file. The framework convert this file into an innovative mathematical structure namely a recursive graph, and solve several optimization problems in order to compute the most efficient role distribution. We show a concrete application of the prototype through RED, an EUREKA/CELTIC European project use-case.
The proceedings contain 25 papers. The topics discussed include: transitivity and propagation of trust in information sources: an analysis in modal logic;the functional dependence relation on hypergraphs of secrets;a ...
ISBN:
(纸本)9783642223587
The proceedings contain 25 papers. The topics discussed include: transitivity and propagation of trust in information sources: an analysis in modal logic;the functional dependence relation on hypergraphs of secrets;a modal framework for relating belief and signed information;on the definability of simulability and bisimilarity by finite epistemic models;applications of logic in social choice theory;a geometric look at manipulation;alternating-time temporal announcement logic;synthesizing strategies for homogenous multi-agent systems with incomplete information;reasoning about joint action and coalitional ability in Kn with intersection;ontology merging as social choice;social commitment delegation and monitoring;verifying team formation protocols with probabilistic model checking;abduction-based search for cooperative answers;reasoning about exceptions to contracts;and probabilistic rule learning in nonmonotonic domains.
Many applications of causal inference, such as finding the relationship between stock prices and news reports, involve both discrete and continuous variables observed over time. Inference with these complex sets of te...
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ISBN:
(纸本)9781577355120
Many applications of causal inference, such as finding the relationship between stock prices and news reports, involve both discrete and continuous variables observed over time. Inference with these complex sets of temporal data, though, has remained difficult and required a number of simplifications. We show that recent approaches for inferring temporal relationships (represented as logical formulas) can be adapted for inference with continuous valued effects. Building on advances in logic, PCTLc (an extension of PCTL with numerical constraints) is introduced here to allow representation and inference of relationships with a mixture of discrete and continuous components. Then, finding significant relationships in the continuous case can be done using the conditional expectation of an effect, rather than its conditional probability. We evaluate this approach on both synthetically generated and actual financial market data, demonstrating that it can allow us to answer different questions than the discrete approach can.
Clause learning is a technique used by backtracking-based propositional satisfiability solvers, where some clauses obtained by analysis of conflicts are added to the formula during backtracking. It has been observed e...
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ISBN:
(纸本)9781577355120
Clause learning is a technique used by backtracking-based propositional satisfiability solvers, where some clauses obtained by analysis of conflicts are added to the formula during backtracking. It has been observed empirically that clause learning does not significantly improve the performance of a solver when restricted to learning clauses of small width only. This experience is supported by lower bound theorems. It is shown that lower bounds on the runtime of width-restricted clause learning follow from lower bounds on the width of resolution proofs. This yields the first lower bounds on width-restricted clause learning for formulas in 3-CNF.
Despite the importance of propositional logic in artificial intelligence, the notion of language independence in the propositional setting (not to be confound with syntax independence) has not received much attention ...
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ISBN:
(纸本)9781577355120
Despite the importance of propositional logic in artificial intelligence, the notion of language independence in the propositional setting (not to be confound with syntax independence) has not received much attention so far. In this paper, we define language independence for a propositional operator as robustness w.r.t. symbol translation. We provide a number of characterizations results for such translations. We motivate the need to focus on symbol translations of restricted types, and identify several families of interest. We identify the computational complexity of recognizing symbol translations from those families. Finally, as a case study, we investigate the robustness of belief revision/merging operators w.r.t. translations of different types. It turns out that rational belief revision/merging operators are not guaranteed to offer the most basic (yet non-trivial) form of language independence;operators based on the Hamming distance do not suffer from this drawback but are less robust than operators based on the drastic distance.
Binary aggregation studies problems in which individuals express yes/no choices over a number of possibly correlated issues, and these individual choices need to be aggregated into a collective choice. We show how sev...
ISBN:
(纸本)9781577355120
Binary aggregation studies problems in which individuals express yes/no choices over a number of possibly correlated issues, and these individual choices need to be aggregated into a collective choice. We show how several classical frameworks of Social Choice Theory, particularly preference and judgment aggregation, can be viewed as binary aggregation problems by designing an appropriate set of integrity constraints for each specific setting. We explore the generality of this framework, showing that it makes available useful techniques both to prove theoretical results, such as a new impossibility theorem in preference aggregation, and to analyse practical problems, such as the characterisation of safe agendas in judgment aggregation in a syntactic way. The framework also allows us to formulate a general definition of paradox that is independent of the domain under consideration, which gives rise to the study of the class of aggregation procedures of generalised dictatorships.
The robot programming and plan language IndiGolog allows for on-line execution of actions and offline projections of programs in dynamic and partly unknown environments. Basic assumptions are that the outcomes of prim...
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ISBN:
(纸本)9781577355120
The robot programming and plan language IndiGolog allows for on-line execution of actions and offline projections of programs in dynamic and partly unknown environments. Basic assumptions are that the outcomes of primitive and sensing actions are correctly modeled, and that the agent is informed about all exogenous events beyond its control. In real-world applications, however, such assumptions do not hold. In fact, an action's outcome is error-prone and sensing results are noisy. In this paper, we present a belief management system in IndiGolog that is able to detect inconsistencies between a robot's modeled belief and what happened in reality. The system furthermore derives explanations and maintains a consistent belief. Our main contributions are (1) a belief management system following a history-based diagnosis approach that allows an agent to actively cope with faulty actions and the occurrence of exogenous events;and (2) an implementation in IndiGolog and experimental results from a delivery domain.
We study the problem of dealing with inconsistency in Description logic (DL) ontologies. We consider inconsistency-tolerant semantics recently proposed in the literature, called AR-semantics and CAR-semantics, which a...
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ISBN:
(纸本)9781577355120
We study the problem of dealing with inconsistency in Description logic (DL) ontologies. We consider inconsistency-tolerant semantics recently proposed in the literature, called AR-semantics and CAR-semantics, which are based on repairing (i.e., modifying) in a minimal way the extensional knowledge (ABox) while keeping the intensional knowledge (TBox) untouched. We study instance checking and conjunctive query entailment under the above inconsistency-tolerant semantics for a wide spectrum of DLs, ranging from tractable ones (EL) to very expressive ones (SHIQ), showing that reasoning under the above semantics is inherently intractable, even for very simple DLs. To the aim of overcoming such a high computational complexity of reasoning, we study sound approximations of the above semantics. Surprisingly, our computational analysis shows that reasoning under the approximated semantics is intractable even for tractable DLs. Finally, we identify suitable language restrictions of such DLs allowing for tractable reasoning under inconsistency-tolerant semantics.
We study the existential closures of several propositional languages L considered recently as target languages for knowledge compilation (KC), namely the incomplete fragments KROM-C, HORN-C, K/H-C, renH-C, AFF, and th...
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ISBN:
(纸本)9781577355120
We study the existential closures of several propositional languages L considered recently as target languages for knowledge compilation (KC), namely the incomplete fragments KROM-C, HORN-C, K/H-C, renH-C, AFF, and the corresponding disjunction closures KROM-C[V], HORN-C[V], K/H-C[V], renH-C[V], and AFF[V]. We analyze the queries, transformations, expressiveness and succinctness of the resulting languages L[∃] in order to locate them in the KC map. As a by-product, we also address several issues concerning disjunction closures that were left open so far. From our investigation, the language HORN - C[V, ∃] (where disjunctions and existential quantifications can be applied to Horn CNF formulae) appears as an interesting target language for the KC purpose, challenging the influential DNNF languages.
We introduce a novel algorithm for actin filament segmentation in 2D TIRFM image sequences. This problem is difficult because actin filaments dynamically change shapes during their growth, and the TIRFM images are usu...
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ISBN:
(纸本)9783642220913
We introduce a novel algorithm for actin filament segmentation in 2D TIRFM image sequences. This problem is difficult because actin filaments dynamically change shapes during their growth, and the TIRFM images are usually noisy. We ask a user to specify the two tips of a filament of interest in the first frame. We then model the segmentation problem in an image sequence as a temporal chain, where its states are tip locations;given candidate tip locations, actin filaments' body points are inferred by a dynamic programming method, which adaptively generates candidate solutions. Combining candidate tip locations and their inferred body points, the temporal chain model is efficiently optimized using another dynamic programming method. Evaluation on noisy TIRFM image sequences demonstrates the accuracy and robustness of this approach.
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