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1207.1350
Daniel Bryce
Daniel Bryce, Subbarao Kambhampati
Cost Sensitive Reachability Heuristics for Handling State Uncertainty
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-60-68
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
While POMDPs provide a general platform for non-deterministic conditional planning under a variety of quality metrics they have limited scalability. On the other hand, non-deterministic conditional planners scale very well, but many lack the ability to optimize plan quality metrics. We present a novel generalization of planning graph based heuristics that helps conditional planners both scale and generate high quality plans when using actions with nonuniform costs. We make empirical comparisons with two state of the art planners to show the benefit of our techniques.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 12:11:17 GMT" } ]
1,341,792,000,000
[ [ "Bryce", "Daniel", "" ], [ "Kambhampati", "Subbarao", "" ] ]
1207.1351
Peter de Waal
Peter de Waal, Linda C. van der Gaag
Stable Independence in Perfect Maps
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-161-168
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the aid of the concept of stable independence we can construct, in an efficient way, a compact representation of a semi-graphoid independence relation. We show that this representation provides a new necessary condition for the existence of a directed perfect map for the relation. The test for this condition is based to a large extent on the transitivity property of a special form of d-separation. The complexity of the test is linear in the size of the representation. The test, moreover, brings the additional benefit that it can be used to guide the early stages of network construction.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 12:12:05 GMT" } ]
1,341,792,000,000
[ [ "de Waal", "Peter", "" ], [ "van der Gaag", "Linda C.", "" ] ]
1207.1353
Kristian Kersting
Kristian Kersting, Tapani Raiko
'Say EM' for Selecting Probabilistic Models for Logical Sequences
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-300-307
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many real world sequences such as protein secondary structures or shell logs exhibit a rich internal structures. Traditional probabilistic models of sequences, however, consider sequences of flat symbols only. Logical hidden Markov models have been proposed as one solution. They deal with logical sequences, i.e., sequences over an alphabet of logical atoms. This comes at the expense of a more complex model selection problem. Indeed, different abstraction levels have to be explored. In this paper, we propose a novel method for selecting logical hidden Markov models from data called SAGEM. SAGEM combines generalized expectation maximization, which optimizes parameters, with structure search for model selection using inductive logic programming refinement operators. We provide convergence and experimental results that show SAGEM's effectiveness.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 12:13:04 GMT" } ]
1,341,792,000,000
[ [ "Kersting", "Kristian", "" ], [ "Raiko", "Tapani", "" ] ]
1207.1354
Kathryn Blackmond Laskey
Kathryn Blackmond Laskey, Paulo da Costa
Of Starships and Klingons: Bayesian Logic for the 23rd Century
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-346-353
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Intelligent systems in an open world must reason about many interacting entities related to each other in diverse ways and having uncertain features and relationships. Traditional probabilistic languages lack the expressive power to handle relational domains. Classical first-order logic is sufficiently expressive, but lacks a coherent plausible reasoning capability. Recent years have seen the emergence of a variety of approaches to integrating first-order logic, probability, and machine learning. This paper presents Multi-entity Bayesian networks (MEBN), a formal system that integrates First Order Logic (FOL) with Bayesian probability theory. MEBN extends ordinary Bayesian networks to allow representation of graphical models with repeated sub-structures, and can express a probability distribution over models of any consistent, finitely axiomatizable first-order theory. We present the logic using an example inspired by the Paramount Series StarTrek.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 12:13:29 GMT" } ]
1,341,792,000,000
[ [ "Laskey", "Kathryn Blackmond", "" ], [ "da Costa", "Paulo", "" ] ]
1207.1355
Anders L. Madsen
Anders L. Madsen
A Differential Semantics of Lazy AR Propagation
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-364-371
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present a differential semantics of Lazy AR Propagation (LARP) in discrete Bayesian networks. We describe how both single and multi dimensional partial derivatives of the evidence may easily be calculated from a junction tree in LARP equilibrium. We show that the simplicity of the calculations stems from the nature of LARP. Based on the differential semantics we describe how variable propagation in the LARP architecture may give access to additional partial derivatives. The cautious LARP (cLARP) scheme is derived to produce a flexible cLARP equilibrium that offers additional opportunities for calculating single and multidimensional partial derivatives of the evidence and subsets of the evidence from a single propagation. The results of an empirical evaluation illustrates how the access to a largely increased number of partial derivatives comes at a low computational cost.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 12:13:36 GMT" } ]
1,341,792,000,000
[ [ "Madsen", "Anders L.", "" ] ]
1207.1356
Yun Peng
Yun Peng, Zhongli Ding
Modifying Bayesian Networks by Probability Constraints
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-459-466
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper deals with the following problem: modify a Bayesian network to satisfy a given set of probability constraints by only change its conditional probability tables, and the probability distribution of the resulting network should be as close as possible to that of the original network. We propose to solve this problem by extending IPFP (iterative proportional fitting procedure) to probability distributions represented by Bayesian networks. The resulting algorithm E-IPFP is further developed to D-IPFP, which reduces the computational cost by decomposing a global EIPFP into a set of smaller local E-IPFP problems. Limited analysis is provided, including the convergence proofs of the two algorithms. Computer experiments were conducted to validate the algorithms. The results are consistent with the theoretical analysis.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 12:14:18 GMT" } ]
1,341,792,000,000
[ [ "Peng", "Yun", "" ], [ "Ding", "Zhongli", "" ] ]
1207.1357
Silja Renooij
Silja Renooij, Linda C. van der Gaag
Exploiting Evidence-dependent Sensitivity Bounds
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-485-492
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Studying the effects of one-way variation of any number of parameters on any number of output probabilities quickly becomes infeasible in practice, especially if various evidence profiles are to be taken into consideration. To provide for identifying the parameters that have a potentially large effect prior to actually performing the analysis, we need properties of sensitivity functions that are independent of the network under study, of the available evidence, or of both. In this paper, we study properties that depend upon just the probability of the entered evidence. We demonstrate that these properties provide for establishing an upper bound on the sensitivity value for a parameter; they further provide for establishing the region in which the vertex of the sensitivity function resides, thereby serving to identify parameters with a low sensitivity value that may still have a large impact on the probability of interest for relatively small parameter variations.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 12:14:29 GMT" } ]
1,341,792,000,000
[ [ "Renooij", "Silja", "" ], [ "van der Gaag", "Linda C.", "" ] ]
1207.1359
Daniel Szer
Daniel Szer, Francois Charpillet, Shlomo Zilberstein
MAA*: A Heuristic Search Algorithm for Solving Decentralized POMDPs
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-576-583
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present multi-agent A* (MAA*), the first complete and optimal heuristic search algorithm for solving decentralized partially-observable Markov decision problems (DEC-POMDPs) with finite horizon. The algorithm is suitable for computing optimal plans for a cooperative group of agents that operate in a stochastic environment such as multirobot coordination, network traffic control, `or distributed resource allocation. Solving such problems efiectively is a major challenge in the area of planning under uncertainty. Our solution is based on a synthesis of classical heuristic search and decentralized control theory. Experimental results show that MAA* has significant advantages. We introduce an anytime variant of MAA* and conclude with a discussion of promising extensions such as an approach to solving infinite horizon problems.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 12:15:09 GMT" } ]
1,341,792,000,000
[ [ "Szer", "Daniel", "" ], [ "Charpillet", "Francois", "" ], [ "Zilberstein", "Shlomo", "" ] ]
1207.1363
Leila Amgoud
Leila Amgoud
A unified setting for inference and decision: An argumentation-based approach
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-26-33
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inferring from inconsistency and making decisions are two problems which have always been treated separately by researchers in Artificial Intelligence. Consequently, different models have been proposed for each category. Different argumentation systems [2, 7, 10, 11] have been developed for handling inconsistency in knowledge bases. Recently, other argumentation systems [3, 4, 8] have been defined for making decisions under uncertainty. The aim of this paper is to present a general argumentation framework in which both inferring from inconsistency and decision making are captured. The proposed framework can be used for decision under uncertainty, multiple criteria decision, rule-based decision and finally case-based decision. Moreover, works on classical decision suppose that the information about environment is coherent, and this no longer required by this general framework.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:02:56 GMT" } ]
1,341,792,000,000
[ [ "Amgoud", "Leila", "" ] ]
1207.1369
Barry Cobb
Barry Cobb, Prakash P. Shenoy
Hybrid Bayesian Networks with Linear Deterministic Variables
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-136-144
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
When a hybrid Bayesian network has conditionally deterministic variables with continuous parents, the joint density function for the continuous variables does not exist. Conditional linear Gaussian distributions can handle such cases when the continuous variables have a multi-variate normal distribution and the discrete variables do not have continuous parents. In this paper, operations required for performing inference with conditionally deterministic variables in hybrid Bayesian networks are developed. These methods allow inference in networks with deterministic variables where continuous variables may be non-Gaussian, and their density functions can be approximated by mixtures of truncated exponentials. There are no constraints on the placement of continuous and discrete nodes in the network.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:05:39 GMT" } ]
1,341,792,000,000
[ [ "Cobb", "Barry", "" ], [ "Shenoy", "Prakash P.", "" ] ]
1207.1370
Arthur Choi
Arthur Choi, Hei Chan, Adnan Darwiche
On Bayesian Network Approximation by Edge Deletion
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-128-135
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of deleting edges from a Bayesian network for the purpose of simplifying models in probabilistic inference. In particular, we propose a new method for deleting network edges, which is based on the evidence at hand. We provide some interesting bounds on the KL-divergence between original and approximate networks, which highlight the impact of given evidence on the quality of approximation and shed some light on good and bad candidates for edge deletion. We finally demonstrate empirically the promise of the proposed edge deletion technique as a basis for approximate inference.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:05:54 GMT" } ]
1,341,792,000,000
[ [ "Choi", "Arthur", "" ], [ "Chan", "Hei", "" ], [ "Darwiche", "Adnan", "" ] ]
1207.1372
Mark Chavira
Mark Chavira, David Allen, Adnan Darwiche
Exploiting Evidence in Probabilistic Inference
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-112-119
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We define the notion of compiling a Bayesian network with evidence and provide a specific approach for evidence-based compilation, which makes use of logical processing. The approach is practical and advantageous in a number of application areas-including maximum likelihood estimation, sensitivity analysis, and MAP computations-and we provide specific empirical results in the domain of genetic linkage analysis. We also show that the approach is applicable for networks that do not contain determinism, and show that it empirically subsumes the performance of the quickscore algorithm when applied to noisy-or networks.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:06:25 GMT" } ]
1,341,792,000,000
[ [ "Chavira", "Mark", "" ], [ "Allen", "David", "" ], [ "Darwiche", "Adnan", "" ] ]
1207.1374
Jennifer Carlson
Jennifer Carlson, Robin R. Murphy
Use of Dempster-Shafer Conflict Metric to Detect Interpretation Inconsistency
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-94-104
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A model of the world built from sensor data may be incorrect even if the sensors are functioning correctly. Possible causes include the use of inappropriate sensors (e.g. a laser looking through glass walls), sensor inaccuracies accumulate (e.g. localization errors), the a priori models are wrong, or the internal representation does not match the world (e.g. a static occupancy grid used with dynamically moving objects). We are interested in the case where the constructed model of the world is flawed, but there is no access to the ground truth that would allow the system to see the discrepancy, such as a robot entering an unknown environment. This paper considers the problem of determining when something is wrong using only the sensor data used to construct the world model. It proposes 11 interpretation inconsistency indicators based on the Dempster-Shafer conflict metric, Con, and evaluates these indicators according to three criteria: ability to distinguish true inconsistency from sensor noise (classification), estimate the magnitude of discrepancies (estimation), and determine the source(s) (if any) of sensing problems in the environment (isolation). The evaluation is conducted using data from a mobile robot with sonar and laser range sensors navigating indoor environments under controlled conditions. The evaluation shows that the Gambino indicator performed best in terms of estimation (at best 0.77 correlation), isolation, and classification of the sensing situation as degraded (7% false negative rate) or normal (0% false positive rate).
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:07:41 GMT" } ]
1,341,792,000,000
[ [ "Carlson", "Jennifer", "" ], [ "Murphy", "Robin R.", "" ] ]
1207.1375
Peter Carbonetto
Peter Carbonetto, Jacek Kisynski, Nando de Freitas, David L Poole
Nonparametric Bayesian Logic
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-85-93
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Bayesian Logic (BLOG) language was recently developed for defining first-order probability models over worlds with unknown numbers of objects. It handles important problems in AI, including data association and population estimation. This paper extends BLOG by adopting generative processes over function spaces - known as nonparametrics in the Bayesian literature. We introduce syntax for reasoning about arbitrary collections of objects, and their properties, in an intuitive manner. By exploiting exchangeability, distributions over unknown objects and their attributes are cast as Dirichlet processes, which resolve difficulties in model selection and inference caused by varying numbers of objects. We demonstrate these concepts with application to citation matching.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:08:11 GMT" } ]
1,341,792,000,000
[ [ "Carbonetto", "Peter", "" ], [ "Kisynski", "Jacek", "" ], [ "de Freitas", "Nando", "" ], [ "Poole", "David L", "" ] ]
1207.1377
Jakub Brzostowski
Jakub Brzostowski, Ryszard Kowalczyk
Efficient algorithm for estimation of qualitative expected utility in possibilistic case-based reasoning
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-69-76
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an efficient algorithm for estimation of possibility based qualitative expected utility. It is useful for decision making mechanisms where each possible decision is assigned a multi-attribute possibility distribution. The computational complexity of ordinary methods calculating the expected utility based on discretization is growing exponentially with the number of attributes, and may become infeasible with a high number of these attributes. We present series of theorems and lemmas proving the correctness of our algorithm that exibits a linear computational complexity. Our algorithm has been applied in the context of selecting the most prospective partners in multi-party multi-attribute negotiation, and can also be used in making decisions about potential offers during the negotiation as other similar problems.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:08:46 GMT" } ]
1,341,792,000,000
[ [ "Brzostowski", "Jakub", "" ], [ "Kowalczyk", "Ryszard", "" ] ]
1207.1378
Changsung Kang
Changsung Kang, Jin Tian
Local Markov Property for Models Satisfying Composition Axiom
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-284-291
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The local Markov condition for a DAG to be an independence map of a probability distribution is well known. For DAGs with latent variables, represented as bi-directed edges in the graph, the local Markov property may invoke exponential number of conditional independencies. This paper shows that the number of conditional independence relations required may be reduced if the probability distributions satisfy the composition axiom. In certain types of graphs, only linear number of conditional independencies are required. The result has applications in testing linear structural equation models with correlated errors.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:09:46 GMT" } ]
1,341,792,000,000
[ [ "Kang", "Changsung", "" ], [ "Tian", "Jin", "" ] ]
1207.1381
Rafay Hammid
Rafay Hammid, Siddhartha Maddi, Amos Johnson, Aaron Bobick, Irfan Essa, Charles Lee Isbell
Unsupervised Activity Discovery and Characterization From Event-Streams
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-251-258
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a framework to discover and characterize different classes of everyday activities from event-streams. We begin by representing activities as bags of event n-grams. This allows us to analyze the global structural information of activities, using their local event statistics. We demonstrate how maximal cliques in an undirected edge-weighted graph of activities, can be used for activity-class discovery in an unsupervised manner. We show how modeling an activity as a variable length Markov process, can be used to discover recurrent event-motifs to characterize the discovered activity-classes. We present results over extensive data-sets, collected from multiple active environments, to show the competence and generalizability of our proposed framework.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:10:35 GMT" } ]
1,341,792,000,000
[ [ "Hammid", "Rafay", "" ], [ "Maddi", "Siddhartha", "" ], [ "Johnson", "Amos", "" ], [ "Bobick", "Aaron", "" ], [ "Essa", "Irfan", "" ], [ "Isbell", "Charles Lee", "" ] ]
1207.1384
Vibhav Gogate
Vibhav Gogate, Rina Dechter, Bozhena Bidyuk, Craig Rindt, James Marca
Modeling Transportation Routines using Hybrid Dynamic Mixed Networks
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-217-224
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper describes a general framework called Hybrid Dynamic Mixed Networks (HDMNs) which are Hybrid Dynamic Bayesian Networks that allow representation of discrete deterministic information in the form of constraints. We propose approximate inference algorithms that integrate and adjust well known algorithmic principles such as Generalized Belief Propagation, Rao-Blackwellised Particle Filtering and Constraint Propagation to address the complexity of modeling and reasoning in HDMNs. We use this framework to model a person's travel activity over time and to predict destination and routes given the current location. We present a preliminary empirical evaluation demonstrating the effectiveness of our modeling framework and algorithms using several variants of the activity model.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:12:38 GMT" } ]
1,341,792,000,000
[ [ "Gogate", "Vibhav", "" ], [ "Dechter", "Rina", "" ], [ "Bidyuk", "Bozhena", "" ], [ "Rindt", "Craig", "" ], [ "Marca", "James", "" ] ]
1207.1385
Vibhav Gogate
Vibhav Gogate, Rina Dechter
Approximate Inference Algorithms for Hybrid Bayesian Networks with Discrete Constraints
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-209-216
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we consider Hybrid Mixed Networks (HMN) which are Hybrid Bayesian Networks that allow discrete deterministic information to be modeled explicitly in the form of constraints. We present two approximate inference algorithms for HMNs that integrate and adjust well known algorithmic principles such as Generalized Belief Propagation, Rao-Blackwellised Importance Sampling and Constraint Propagation to address the complexity of modeling and reasoning in HMNs. We demonstrate the performance of our approximate inference algorithms on randomly generated HMNs.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:12:59 GMT" } ]
1,341,792,000,000
[ [ "Gogate", "Vibhav", "" ], [ "Dechter", "Rina", "" ] ]
1207.1386
Norman Ferns
Norman Ferns, Prakash Panangaden, Doina Precup
Metrics for Markov Decision Processes with Infinite State Spaces
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-201-208
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present metrics for measuring state similarity in Markov decision processes (MDPs) with infinitely many states, including MDPs with continuous state spaces. Such metrics provide a stable quantitative analogue of the notion of bisimulation for MDPs, and are suitable for use in MDP approximation. We show that the optimal value function associated with a discounted infinite horizon planning task varies continuously with respect to our metric distances.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:13:21 GMT" } ]
1,341,792,000,000
[ [ "Ferns", "Norman", "" ], [ "Panangaden", "Prakash", "" ], [ "Precup", "Doina", "" ] ]
1207.1391
Yaxin Liu
Yaxin Liu, Sven Koenig
Existence and Finiteness Conditions for Risk-Sensitive Planning: Results and Conjectures
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-354-363
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Decision-theoretic planning with risk-sensitive planning objectives is important for building autonomous agents or decision-support systems for real-world applications. However, this line of research has been largely ignored in the artificial intelligence and operations research communities since planning with risk-sensitive planning objectives is more complicated than planning with risk-neutral planning objectives. To remedy this situation, we derive conditions that guarantee that the optimal expected utilities of the total plan-execution reward exist and are finite for fully observable Markov decision process models with non-linear utility functions. In case of Markov decision process models with both positive and negative rewards, most of our results hold for stationary policies only, but we conjecture that they can be generalized to non stationary policies.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:15:31 GMT" } ]
1,341,792,000,000
[ [ "Liu", "Yaxin", "" ], [ "Koenig", "Sven", "" ] ]
1207.1394
Andreas Krause
Andreas Krause, Carlos E. Guestrin
Near-optimal Nonmyopic Value of Information in Graphical Models
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-324-331
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A fundamental issue in real-world systems, such as sensor networks, is the selection of observations which most effectively reduce uncertainty. More specifically, we address the long standing problem of nonmyopically selecting the most informative subset of variables in a graphical model. We present the first efficient randomized algorithm providing a constant factor (1-1/e-epsilon) approximation guarantee for any epsilon > 0 with high confidence. The algorithm leverages the theory of submodular functions, in combination with a polynomial bound on sample complexity. We furthermore prove that no polynomial time algorithm can provide a constant factor approximation better than (1 - 1/e) unless P = NP. Finally, we provide extensive evidence of the effectiveness of our method on two complex real-world datasets.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:16:25 GMT" } ]
1,341,792,000,000
[ [ "Krause", "Andreas", "" ], [ "Guestrin", "Carlos E.", "" ] ]
1207.1397
Guilin Qi
Guilin Qi, Weiru Liu, David A. Bell
A Revision-Based Approach to Resolving Conflicting Information
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-477-484
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose a revision-based approach for conflict resolution by generalizing the Disjunctive Maxi-Adjustment (DMA) approach (Benferhat et al. 2004). Revision operators can be classified into two different families: the model-based ones and the formula-based ones. So the revision-based approach has two different versions according to which family of revision operators is chosen. Two particular revision operators are considered, one is the Dalal's revision operator, which is a model-based revision operator, and the other is the cardinality-maximal based revision operator, which is a formulabased revision operator. When the Dalal's revision operator is chosen, the revision-based approach is independent of the syntactic form in each stratum and it captures some notion of minimal change. When the cardinalitymaximal based revision operator is chosen, the revision-based approach is equivalent to the DMA approach. We also show that both approaches are computationally easier than the DMA approach.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:18:06 GMT" } ]
1,341,792,000,000
[ [ "Qi", "Guilin", "" ], [ "Liu", "Weiru", "" ], [ "Bell", "David A.", "" ] ]
1207.1398
Avi Pfeffer
Avi Pfeffer, Terry Tai
Asynchronous Dynamic Bayesian Networks
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-467-476
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Systems such as sensor networks and teams of autonomous robots consist of multiple autonomous entities that interact with each other in a distributed, asynchronous manner. These entities need to keep track of the state of the system as it evolves. Asynchronous systems lead to special challenges for monitoring, as nodes must update their beliefs independently of each other and no central coordination is possible. Furthermore, the state of the system continues to change as beliefs are being updated. Previous approaches to developing distributed asynchronous probabilistic reasoning systems have used static models. We present an approach using dynamic models, that take into account the way the system changes state over time. Our approach, which is based on belief propagation, is fully distributed and asynchronous, and allows the world to keep on changing as messages are being sent around. Experimental results show that our approach compares favorably to the factored frontier algorithm.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:18:25 GMT" } ]
1,341,792,000,000
[ [ "Pfeffer", "Avi", "" ], [ "Tai", "Terry", "" ] ]
1207.1401
Uri Nodelman
Uri Nodelman, Daphne Koller, Christian R. Shelton
Expectation Propagation for Continuous Time Bayesian Networks
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-431-440
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Continuous time Bayesian networks (CTBNs) describe structured stochastic processes with finitely many states that evolve over continuous time. A CTBN is a directed (possibly cyclic) dependency graph over a set of variables, each of which represents a finite state continuous time Markov process whose transition model is a function of its parents. As shown previously, exact inference in CTBNs is intractable. We address the problem of approximate inference, allowing for general queries conditioned on evidence over continuous time intervals and at discrete time points. We show how CTBNs can be parameterized within the exponential family, and use that insight to develop a message passing scheme in cluster graphs and allows us to apply expectation propagation to CTBNs. The clusters in our cluster graph do not contain distributions over the cluster variables at individual time points, but distributions over trajectories of the variables throughout a duration. Thus, unlike discrete time temporal models such as dynamic Bayesian networks, we can adapt the time granularity at which we reason for different variables and in different conditions.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:19:23 GMT" } ]
1,341,792,000,000
[ [ "Nodelman", "Uri", "" ], [ "Koller", "Daphne", "" ], [ "Shelton", "Christian R.", "" ] ]
1207.1402
Uri Nodelman
Uri Nodelman, Christian R. Shelton, Daphne Koller
Expectation Maximization and Complex Duration Distributions for Continuous Time Bayesian Networks
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-421-430
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Continuous time Bayesian networks (CTBNs) describe structured stochastic processes with finitely many states that evolve over continuous time. A CTBN is a directed (possibly cyclic) dependency graph over a set of variables, each of which represents a finite state continuous time Markov process whose transition model is a function of its parents. We address the problem of learning the parameters and structure of a CTBN from partially observed data. We show how to apply expectation maximization (EM) and structural expectation maximization (SEM) to CTBNs. The availability of the EM algorithm allows us to extend the representation of CTBNs to allow a much richer class of transition durations distributions, known as phase distributions. This class is a highly expressive semi-parametric representation, which can approximate any duration distribution arbitrarily closely. This extension to the CTBN framework addresses one of the main limitations of both CTBNs and DBNs - the restriction to exponentially / geometrically distributed duration. We present experimental results on a real data set of people's life spans, showing that our algorithm learns reasonable models - structure and parameters - from partially observed data, and, with the use of phase distributions, achieves better performance than DBNs.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:19:39 GMT" } ]
1,341,792,000,000
[ [ "Nodelman", "Uri", "" ], [ "Shelton", "Christian R.", "" ], [ "Koller", "Daphne", "" ] ]
1207.1405
Joris Mooij
Joris Mooij, Hilbert Kappen
Sufficient conditions for convergence of Loopy Belief Propagation
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-396-403
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive novel sufficient conditions for convergence of Loopy Belief Propagation (also known as the Sum-Product algorithm) to a unique fixed point. Our results improve upon previously known conditions. For binary variables with (anti-)ferromagnetic interactions, our conditions seem to be sharp.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:20:27 GMT" } ]
1,341,792,000,000
[ [ "Mooij", "Joris", "" ], [ "Kappen", "Hilbert", "" ] ]
1207.1407
Robert Mateescu
Robert Mateescu, Rina Dechter
The Relationship Between AND/OR Search and Variable Elimination
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-380-387
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we compare search and inference in graphical models through the new framework of AND/OR search. Specifically, we compare Variable Elimination (VE) and memoryintensive AND/OR Search (AO) and place algorithms such as graph-based backjumping and no-good and good learning, as well as Recursive Conditioning [7] and Value Elimination [2] within the AND/OR search framework.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:21:01 GMT" } ]
1,341,792,000,000
[ [ "Mateescu", "Robert", "" ], [ "Dechter", "Rina", "" ] ]
1207.1408
Sridhar Mahadevan
Sridhar Mahadevan
Representation Policy Iteration
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-372-379
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper addresses a fundamental issue central to approximation methods for solving large Markov decision processes (MDPs): how to automatically learn the underlying representation for value function approximation? A novel theoretically rigorous framework is proposed that automatically generates geometrically customized orthonormal sets of basis functions, which can be used with any approximate MDP solver like least squares policy iteration (LSPI). The key innovation is a coordinate-free representation of value functions, using the theory of smooth functions on a Riemannian manifold. Hodge theory yields a constructive method for generating basis functions for approximating value functions based on the eigenfunctions of the self-adjoint (Laplace-Beltrami) operator on manifolds. In effect, this approach performs a global Fourier analysis on the state space graph to approximate value functions, where the basis functions reflect the largescale topology of the underlying state space. A new class of algorithms called Representation Policy Iteration (RPI) are presented that automatically learn both basis functions and approximately optimal policies. Illustrative experiments compare the performance of RPI with that of LSPI using two handcoded basis functions (RBF and polynomial state encodings).
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:21:20 GMT" } ]
1,341,792,000,000
[ [ "Mahadevan", "Sridhar", "" ] ]
1207.1412
Trey Smith
Trey Smith, Reid Simmons
Point-Based POMDP Algorithms: Improved Analysis and Implementation
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-542-549
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Existing complexity bounds for point-based POMDP value iteration algorithms focus either on the curse of dimensionality or the curse of history. We derive a new bound that relies on both and uses the concept of discounted reachability; our conclusions may help guide future algorithm design. We also discuss recent improvements to our (point-based) heuristic search value iteration algorithm. Our new implementation calculates tighter initial bounds, avoids solving linear programs, and makes more effective use of sparsity.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:23:13 GMT" } ]
1,341,792,000,000
[ [ "Smith", "Trey", "" ], [ "Simmons", "Reid", "" ] ]
1207.1415
Scott Sanner
Scott Sanner, Craig Boutilier
Approximate Linear Programming for First-order MDPs
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-509-517
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a new approximate solution technique for first-order Markov decision processes (FOMDPs). Representing the value function linearly w.r.t. a set of first-order basis functions, we compute suitable weights by casting the corresponding optimization as a first-order linear program and show how off-the-shelf theorem prover and LP software can be effectively used. This technique allows one to solve FOMDPs independent of a specific domain instantiation; furthermore, it allows one to determine bounds on approximation error that apply equally to all domain instantiations. We apply this solution technique to the task of elevator scheduling with a rich feature space and multi-criteria additive reward, and demonstrate that it outperforms a number of intuitive, heuristicallyguided policies.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:24:08 GMT" } ]
1,341,792,000,000
[ [ "Sanner", "Scott", "" ], [ "Boutilier", "Craig", "" ] ]
1207.1416
Matthew Rudary
Matthew Rudary, Satinder Singh, David Wingate
Predictive Linear-Gaussian Models of Stochastic Dynamical Systems
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-501-508
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Models of dynamical systems based on predictive state representations (PSRs) are defined strictly in terms of observable quantities, in contrast with traditional models (such as Hidden Markov Models) that use latent variables or statespace representations. In addition, PSRs have an effectively infinite memory, allowing them to model some systems that finite memory-based models cannot. Thus far, PSR models have primarily been developed for domains with discrete observations. Here, we develop the Predictive Linear-Gaussian (PLG) model, a class of PSR models for domains with continuous observations. We show that PLG models subsume Linear Dynamical System models (also called Kalman filter models or state-space models) while using fewer parameters. We also introduce an algorithm to estimate PLG parameters from data, and contrast it with standard Expectation Maximization (EM) algorithms used to estimate Kalman filter parameters. We show that our algorithm is a consistent estimation procedure and present preliminary empirical results suggesting that our algorithm outperforms EM, particularly as the model dimension increases.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:24:39 GMT" } ]
1,341,792,000,000
[ [ "Rudary", "Matthew", "" ], [ "Singh", "Satinder", "" ], [ "Wingate", "David", "" ] ]
1207.1418
Alice X. Zheng
Alice X. Zheng, Irina Rish, Alina Beygelzimer
Efficient Test Selection in Active Diagnosis via Entropy Approximation
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-675-682
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of diagnosing faults in a system represented by a Bayesian network, where diagnosis corresponds to recovering the most likely state of unobserved nodes given the outcomes of tests (observed nodes). Finding an optimal subset of tests in this setting is intractable in general. We show that it is difficult even to compute the next most-informative test using greedy test selection, as it involves several entropy terms whose exact computation is intractable. We propose an approximate approach that utilizes the loopy belief propagation infrastructure to simultaneously compute approximations of marginal and conditional entropies on multiple subsets of nodes. We apply our method to fault diagnosis in computer networks, and show the algorithm to be very effective on realistic Internet-like topologies. We also provide theoretical justification for the greedy test selection approach, along with some performance guarantees.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:26:12 GMT" } ]
1,341,792,000,000
[ [ "Zheng", "Alice X.", "" ], [ "Rish", "Irina", "" ], [ "Beygelzimer", "Alina", "" ] ]
1207.1422
Changhe Yuan
Changhe Yuan, Marek J. Druzdzel
Importance Sampling in Bayesian Networks: An Influence-Based Approximation Strategy for Importance Functions
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-650-657
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One of the main problems of importance sampling in Bayesian networks is representation of the importance function, which should ideally be as close as possible to the posterior joint distribution. Typically, we represent an importance function as a factorization, i.e., product of conditional probability tables (CPTs). Given diagnostic evidence, we do not have explicit forms for the CPTs in the networks. We first derive the exact form for the CPTs of the optimal importance function. Since the calculation is hard, we usually only use their approximations. We review several popular strategies and point out their limitations. Based on an analysis of the influence of evidence, we propose a method for approximating the exact form of importance function by explicitly modeling the most important additional dependence relations introduced by evidence. Our experimental results show that the new approximation strategy offers an immediate improvement in the quality of the importance function.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:28:23 GMT" } ]
1,341,792,000,000
[ [ "Yuan", "Changhe", "" ], [ "Druzdzel", "Marek J.", "" ] ]
1207.1426
Max Welling
Max Welling, Thomas P. Minka, Yee Whye Teh
Structured Region Graphs: Morphing EP into GBP
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-609-614
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
GBP and EP are two successful algorithms for approximate probabilistic inference, which are based on different approximation strategies. An open problem in both algorithms has been how to choose an appropriate approximation structure. We introduce 'structured region graphs', a formalism which marries these two strategies, reveals a deep connection between them, and suggests how to choose good approximation structures. In this formalism, each region has an internal structure which defines an exponential family, whose sufficient statistics must be matched by the parent region. Reduction operators on these structures allow conversion between EP and GBP free energies. Thus it is revealed that all EP approximations on discrete variables are special cases of GBP, and conversely that some wellknown GBP approximations, such as overlapping squares, are special cases of EP. Furthermore, region graphs derived from EP have a number of good structural properties, including maxent-normality and overall counting number of one. The result is a convenient framework for producing high-quality approximations with a user-adjustable level of complexity
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:29:26 GMT" } ]
1,341,792,000,000
[ [ "Welling", "Max", "" ], [ "Minka", "Thomas P.", "" ], [ "Teh", "Yee Whye", "" ] ]
1207.1427
Segev Wasserkrug
Segev Wasserkrug, Avigdor Gal, Opher Etzion
A Model for Reasoning with Uncertain Rules in Event Composition Systems
Appears in Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (UAI2005)
null
null
UAI-P-2005-PG-599-608
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent years, there has been an increased need for the use of active systems - systems required to act automatically based on events, or changes in the environment. Such systems span many areas, from active databases to applications that drive the core business processes of today's enterprises. However, in many cases, the events to which the system must respond are not generated by monitoring tools, but must be inferred from other events based on complex temporal predicates. In addition, in many applications, such inference is inherently uncertain. In this paper, we introduce a formal framework for knowledge representation and reasoning enabling such event inference. Based on probability theory, we define the representation of the associated uncertainty. In addition, we formally define the probability space, and show how the relevant probabilities can be calculated by dynamically constructing a Bayesian network. To the best of our knowledge, this is the first work that enables taking such uncertainty into account in the context of active systems. herefore, our contribution is twofold: We formally define the representation and semantics of event composition for probabilistic settings, and show how to apply these extensions to the quantification of the occurrence probability of events. These results enable any active system to handle such uncertainty.
[ { "version": "v1", "created": "Wed, 4 Jul 2012 16:29:47 GMT" } ]
1,341,792,000,000
[ [ "Wasserkrug", "Segev", "" ], [ "Gal", "Avigdor", "" ], [ "Etzion", "Opher", "" ] ]
1207.1501
Gol Kim
Gol Kim, Fei Ye
Super-Mixed Multiple Attribute Group Decision Making Method Based on Hybrid Fuzzy Grey Relation Approach Degree
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The feature of our method different from other fuzzy grey relation method for supermixed multiple attribute group decision-making is that all of the subjective and objective weights are obtained by interval grey number and that the group decisionmaking is performed based on the relative approach degree of grey TOPSIS, the relative approach degree of grey incidence and the relative membership degree of grey incidence using 4-dimensional Euclidean distance. The weighted Borda method is used to obtain final rank by using the results of four methods. An example shows the applicability of the proposed approach.
[ { "version": "v1", "created": "Fri, 6 Jul 2012 01:26:39 GMT" } ]
1,342,051,200,000
[ [ "Kim", "Gol", "" ], [ "Ye", "Fei", "" ] ]
1207.1534
Gol Kim
Gol Kim, Yunchol Jong, Sifeng Liu
Generalized Hybrid Grey Relation Method for Multiple Attribute Mixed Type Decision Making
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The multiple attribute mixed type decision making is performed by four methods, that is, the relative approach degree of grey TOPSIS method, the relative approach degree of grey incidence, the relative membership degree of grey incidence and the grey relation relative approach degree method using the maximum entropy estimation, respectively. In these decision making methods, the grey incidence degree in four-dimensional Euclidean space is used. The final arrangement result is obtained by weighted Borda method. An example illustrates the applicability of the proposed approach.
[ { "version": "v1", "created": "Fri, 6 Jul 2012 06:44:08 GMT" } ]
1,342,051,200,000
[ [ "Kim", "Gol", "" ], [ "Jong", "Yunchol", "" ], [ "Liu", "Sifeng", "" ] ]
1207.1811
George Katsirelos
George Katsirelos and Nina Narodytska and Toby Walsh
The SeqBin Constraint Revisited
Longer version of paper accepted at CP 2012
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the SeqBin constraint. This meta-constraint subsumes a number of important global constraints like Change, Smooth and IncreasingNValue. We show that the previously proposed filtering algorithm for SeqBin has two drawbacks even under strong restrictions: it does not detect bounds disentailment and it is not idempotent. We identify the cause for these problems, and propose a new propagator that overcomes both issues. Our algorithm is based on a connection to the problem of finding a path of a given cost in a restricted $n$-partite graph. Our propagator enforces domain consistency in O(nd^2) and, for special cases of SeqBin that include Change, Smooth and IncreasingNValue, in O(nd) time.
[ { "version": "v1", "created": "Sat, 7 Jul 2012 16:21:53 GMT" } ]
1,426,809,600,000
[ [ "Katsirelos", "George", "" ], [ "Narodytska", "Nina", "" ], [ "Walsh", "Toby", "" ] ]
1207.2373
Mohamed Achraf Ben Mohamed Mr.
Mohamed Achraf Ben Mohamed, Dhaou El Ghoul, Mohamed Amine Nahdi, Mourad Mars and Mounir Zrigui
Arabic CALL system based on pedagogically indexed text
The 2011 International Conference on Artificial Intelligence (ICAI'11), 2011, WORLDCOMP'11, Las Vegas, Nevada, USA
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This article introduces the benefits of using computer as a tool for foreign language teaching and learning. It describes the effect of using Natural Language Processing (NLP) tools for learning Arabic. The technique explored in this particular case is the employment of pedagogically indexed corpora. This text-based method provides the teacher the advantage of building activities based on texts adapted to a particular pedagogical situation. This paper also presents ARAC: a Platform dedicated to language educators allowing them to create activities within their own pedagogical area of interest.
[ { "version": "v1", "created": "Tue, 10 Jul 2012 14:34:24 GMT" } ]
1,341,964,800,000
[ [ "Mohamed", "Mohamed Achraf Ben", "" ], [ "Ghoul", "Dhaou El", "" ], [ "Nahdi", "Mohamed Amine", "" ], [ "Mars", "Mourad", "" ], [ "Zrigui", "Mounir", "" ] ]
1207.2459
Mohamed Ali Mahjoub
Fradj Ben Lamine (sage), Karim Kalti (sage), Mohamed Ali Mahjoub (SAGE)
Etude de Mod\`eles \`a base de r\'eseaux Bay\'esiens pour l'aide au diagnostic de tumeurs c\'er\'ebrales
Journ\'ees francophones d'ing\'enierie des connaissances, France (2012)
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This article describes different models based on Bayesian networks RB modeling expertise in the diagnosis of brain tumors. Indeed, they are well adapted to the representation of the uncertainty in the process of diagnosis of these tumors. In our work, we first tested several structures derived from the Bayesian network reasoning performed by doctors on the one hand and structures generated automatically on the other. This step aims to find the best structure that increases diagnostic accuracy. The machine learning algorithms relate MWST-EM algorithms, SEM and SEM + T. To estimate the parameters of the Bayesian network from a database incomplete, we have proposed an extension of the EM algorithm by adding a priori knowledge in the form of the thresholds calculated by the first phase of the algorithm RBE . The very encouraging results obtained are discussed at the end of the paper
[ { "version": "v1", "created": "Tue, 10 Jul 2012 19:58:05 GMT" } ]
1,341,964,800,000
[ [ "Lamine", "Fradj Ben", "", "sage" ], [ "Kalti", "Karim", "", "sage" ], [ "Mahjoub", "Mohamed Ali", "", "SAGE" ] ]
1207.2592
Gol Kim
Gol Kim (Center of Natural Science, University of Sciences, Pyongyang, DPR Korea)
Novel Grey Interval Weight Determining and Hybrid Grey Interval Relation Method in Multiple Attribute Decision-Making
arXiv admin note: substantial text overlap with arXiv:1207.1501
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper proposes a grey interval relation TOPSIS for the decision making in which all of the attribute weights and attribute values are given by the interval grey numbers. The feature of our method different from other grey relation decision-making is that all of the subjective and objective weights are obtained by interval grey number and that decisionmaking is performed based on the relative approach degree of grey TOPSIS, the relative approach degree of grey incidence and the relative membership degree of grey incidence using 2-dimensional Euclidean distance. The weighted Borda method is used for combining the results of three methods. An example shows the applicability of the proposed approach.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 10:54:15 GMT" } ]
1,342,051,200,000
[ [ "Kim", "Gol", "", "Center of Natural Science, University of Sciences, Pyongyang,\n DPR Korea" ] ]
1207.3270
Anastasios Skarlatidis
Anastasios Skarlatidis, Georgios Paliouras, Alexander Artikis, George A. Vouros
Probabilistic Event Calculus for Event Recognition
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Symbolic event recognition systems have been successfully applied to a variety of application domains, extracting useful information in the form of events, allowing experts or other systems to monitor and respond when significant events are recognised. In a typical event recognition application, however, these systems often have to deal with a significant amount of uncertainty. In this paper, we address the issue of uncertainty in logic-based event recognition by extending the Event Calculus with probabilistic reasoning. Markov Logic Networks are a natural candidate for our logic-based formalism. However, the temporal semantics of the Event Calculus introduce a number of challenges for the proposed model. We show how and under what assumptions we can overcome these problems. Additionally, we study how probabilistic modelling changes the behaviour of the formalism, affecting its key property, the inertia of fluents. Furthermore, we demonstrate the advantages of the probabilistic Event Calculus through examples and experiments in the domain of activity recognition, using a publicly available dataset for video surveillance.
[ { "version": "v1", "created": "Fri, 13 Jul 2012 14:57:35 GMT" }, { "version": "v2", "created": "Thu, 15 Aug 2013 11:13:05 GMT" } ]
1,376,611,200,000
[ [ "Skarlatidis", "Anastasios", "" ], [ "Paliouras", "Georgios", "" ], [ "Artikis", "Alexander", "" ], [ "Vouros", "George A.", "" ] ]
1207.3543
Reza Keyvan
Mohammadreza Keyvanpour and Fereshteh Azizani
Classification of Approaches and Challenges of Frequent Subgraphs Mining in Biological Networks
null
International Journal of Advanced Engineering Sciences and Technologies, Vol No. 4, Issue No. 2, 014 - 017, 2011
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Understanding the structure and dynamics of biological networks is one of the important challenges in system biology. In addition, increasing amount of experimental data in biological networks necessitate the use of efficient methods to analyze these huge amounts of data. Such methods require to recognize common patterns to analyze data. As biological networks can be modeled by graphs, the problem of common patterns recognition is equivalent with frequent sub graph mining in a set of graphs. In this paper, at first the challenges of frequent subgrpahs mining in biological networks are introduced and the existing approaches are classified for each challenge. then the algorithms are analyzed on the basis of the type of the approach they apply for each of the challenges.
[ { "version": "v1", "created": "Sun, 15 Jul 2012 21:11:44 GMT" } ]
1,342,483,200,000
[ [ "Keyvanpour", "Mohammadreza", "" ], [ "Azizani", "Fereshteh", "" ] ]
1207.3855
Gol Kim
Gol Kim, Yunchol Jong, Sifeng Liu, Choe Rim Shong
Hybrid Grey Interval Relation Decision-Making in Artistic Talent Evaluation of Player
arXiv admin note: substantial text overlap with arXiv:1207.2592
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper proposes a grey interval relation TOPSIS method for the decision making in which all of the attribute weights and attribute values are given by the interval grey numbers. In this paper, all of the subjective and objective weights are obtained by interval grey number and decision-making is based on four methods such as the relative approach degree of grey TOPSIS, the relative approach degree of grey incidence and the relative approach degree method using the maximum entropy estimation using 2-dimensional Euclidean distance. A multiple attribute decision-making example for evaluation of artistic talent of Kayagum (stringed Korean harp) players is given to show practicability of the proposed approach.
[ { "version": "v1", "created": "Tue, 17 Jul 2012 01:36:39 GMT" } ]
1,342,569,600,000
[ [ "Kim", "Gol", "" ], [ "Jong", "Yunchol", "" ], [ "Liu", "Sifeng", "" ], [ "Shong", "Choe Rim", "" ] ]
1207.3863
Nitin Yadav
Nitin Yadav and Sebastian Sardina
Qualitative Approximate Behavior Composition
null
In Proceedings of the European Conference on Logics in Artificial Intelligence (JELIA), volume 7519 of LNCS, pages 450-462, 2012
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The behavior composition problem involves automatically building a controller that is able to realize a desired, but unavailable, target system (e.g., a house surveillance) by suitably coordinating a set of available components (e.g., video cameras, blinds, lamps, a vacuum cleaner, phones, etc.) Previous work has almost exclusively aimed at bringing about the desired component in its totality, which is highly unsatisfactory for unsolvable problems. In this work, we develop an approach for approximate behavior composition without departing from the classical setting, thus making the problem applicable to a much wider range of cases. Based on the notion of simulation, we characterize what a maximal controller and the "closest" implementable target module (optimal approximation) are, and show how these can be computed using ATL model checking technology for a special case. We show the uniqueness of optimal approximations, and prove their soundness and completeness with respect to their imported controllers.
[ { "version": "v1", "created": "Tue, 17 Jul 2012 02:56:11 GMT" } ]
1,467,676,800,000
[ [ "Yadav", "Nitin", "" ], [ "Sardina", "Sebastian", "" ] ]
1207.3874
Nitin Yadav
Nitin Yadav and Sebastian Sardina
Reasoning about Agent Programs using ATL-like Logics
null
In Proceedings of the European Conference on Logics in Artificial Intelligence (JELIA), volume 7519 of LNCS, pages 437-449, 2012
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a variant of Alternating-time Temporal Logic (ATL) grounded in the agents' operational know-how, as defined by their libraries of abstract plans. Inspired by ATLES, a variant itself of ATL, it is possible in our logic to explicitly refer to "rational" strategies for agents developed under the Belief-Desire-Intention agent programming paradigm. This allows us to express and verify properties of BDI systems using ATL-type logical frameworks.
[ { "version": "v1", "created": "Tue, 17 Jul 2012 04:10:28 GMT" } ]
1,467,676,800,000
[ [ "Yadav", "Nitin", "" ], [ "Sardina", "Sebastian", "" ] ]
1207.4107
Charles Gretton
Charles Gretton, Sylvie Thiebaux
Exploiting First-Order Regression in Inductive Policy Selection
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-217-225
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of computing optimal generalised policies for relational Markov decision processes. We describe an approach combining some of the benefits of purely inductive techniques with those of symbolic dynamic programming methods. The latter reason about the optimal value function using first-order decision theoretic regression and formula rewriting, while the former, when provided with a suitable hypotheses language, are capable of generalising value functions or policies for small instances. Our idea is to use reasoning and in particular classical first-order regression to automatically generate a hypotheses language dedicated to the domain at hand, which is then used as input by an inductive solver. This approach avoids the more complex reasoning of symbolic dynamic programming while focusing the inductive solver's attention on concepts that are specifically relevant to the optimal value function for the domain considered.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:40:15 GMT" } ]
1,342,656,000,000
[ [ "Gretton", "Charles", "" ], [ "Thiebaux", "Sylvie", "" ] ]
1207.4111
Phan Giang
Phan H. Giang, Sathyakama Sandilya
Decision Making for Symbolic Probability
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-185-192
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper proposes a decision theory for a symbolic generalization of probability theory (SP). Darwiche and Ginsberg [2,3] proposed SP to relax the requirement of using numbers for uncertainty while preserving desirable patterns of Bayesian reasoning. SP represents uncertainty by symbolic supports that are ordered partially rather than completely as in the case of standard probability. We show that a preference relation on acts that satisfies a number of intuitive postulates is represented by a utility function whose domain is a set of pairs of supports. We argue that a subjective interpretation is as useful and appropriate for SP as it is for numerical probability. It is useful because the subjective interpretation provides a basis for uncertainty elicitation. It is appropriate because we can provide a decision theory that explains how preference on acts is based on support comparison.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:42:08 GMT" }, { "version": "v2", "created": "Tue, 31 Jul 2012 17:17:25 GMT" } ]
1,343,779,200,000
[ [ "Giang", "Phan H.", "" ], [ "Sandilya", "Sathyakama", "" ] ]
1207.4114
Norman Ferns
Norman Ferns, Prakash Panangaden, Doina Precup
Metrics for Finite Markov Decision Processes
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-162-169
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present metrics for measuring the similarity of states in a finite Markov decision process (MDP). The formulation of our metrics is based on the notion of bisimulation for MDPs, with an aim towards solving discounted infinite horizon reinforcement learning tasks. Such metrics can be used to aggregate states, as well as to better structure other value function approximators (e.g., memory-based or nearest-neighbor approximators). We provide bounds that relate our metric distances to the optimal values of states in the given MDP.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:43:04 GMT" } ]
1,342,656,000,000
[ [ "Ferns", "Norman", "" ], [ "Panangaden", "Prakash", "" ], [ "Precup", "Doina", "" ] ]
1207.4115
Zhengzhu Feng
Zhengzhu Feng, Richard Dearden, Nicolas Meuleau, Richard Washington
Dynamic Programming for Structured Continuous Markov Decision Problems
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-154-161
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe an approach for exploiting structure in Markov Decision Processes with continuous state variables. At each step of the dynamic programming, the state space is dynamically partitioned into regions where the value function is the same throughout the region. We first describe the algorithm for piecewise constant representations. We then extend it to piecewise linear representations, using techniques from POMDPs to represent and reason about linear surfaces efficiently. We show that for complex, structured problems, our approach exploits the natural structure so that optimal solutions can be computed efficiently.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:43:21 GMT" } ]
1,342,656,000,000
[ [ "Feng", "Zhengzhu", "" ], [ "Dearden", "Richard", "" ], [ "Meuleau", "Nicolas", "" ], [ "Washington", "Richard", "" ] ]
1207.4116
Zhengzhu Feng
Zhengzhu Feng, Shlomo Zilberstein
Region-Based Incremental Pruning for POMDPs
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-146-153
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a major improvement to the incremental pruning algorithm for solving partially observable Markov decision processes. Our technique targets the cross-sum step of the dynamic programming (DP) update, a key source of complexity in POMDP algorithms. Instead of reasoning about the whole belief space when pruning the cross-sums, our algorithm divides the belief space into smaller regions and performs independent pruning in each region. We evaluate the benefits of the new technique both analytically and experimentally, and show that it produces very significant performance gains. The results contribute to the scalability of POMDP algorithms to domains that cannot be handled by the best existing techniques.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:43:38 GMT" } ]
1,342,656,000,000
[ [ "Feng", "Zhengzhu", "" ], [ "Zilberstein", "Shlomo", "" ] ]
1207.4117
Didier Dubois
Didier Dubois, Helene Fargier
A Unified framework for order-of-magnitude confidence relations
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-138-145
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The aim of this work is to provide a unified framework for ordinal representations of uncertainty lying at the crosswords between possibility and probability theories. Such confidence relations between events are commonly found in monotonic reasoning, inconsistency management, or qualitative decision theory. They start either from probability theory, making it more qualitative, or from possibility theory, making it more expressive. We show these two trends converge to a class of genuine probability theories. We provide characterization results for these useful tools that preserve the qualitative nature of possibility rankings, while enjoying the power of expressivity of additive representations.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:44:05 GMT" }, { "version": "v2", "created": "Mon, 6 Aug 2012 17:54:10 GMT" } ]
1,344,297,600,000
[ [ "Dubois", "Didier", "" ], [ "Fargier", "Helene", "" ] ]
1207.4119
Rina Dechter
Rina Dechter, Robert Mateescu
Mixtures of Deterministic-Probabilistic Networks and their AND/OR Search Space
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-120-129
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The paper introduces mixed networks, a new framework for expressing and reasoning with probabilistic and deterministic information. The framework combines belief networks with constraint networks, defining the semantics and graphical representation. We also introduce the AND/OR search space for graphical models, and develop a new linear space search algorithm. This provides the basis for understanding the benefits of processing the constraint information separately, resulting in the pruning of the search space. When the constraint part is tractable or has a small number of solutions, using the mixed representation can be exponentially more effective than using pure belief networks which odel constraints as conditional probability tables.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:44:42 GMT" } ]
1,342,656,000,000
[ [ "Dechter", "Rina", "" ], [ "Mateescu", "Robert", "" ] ]
1207.4120
Peter de Waal
Peter de Waal, Linda C. van der Gaag
Stable Independance and Complexity of Representation
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-112-119
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The representation of independence relations generally builds upon the well-known semigraphoid axioms of independence. Recently, a representation has been proposed that captures a set of dominant statements of an independence relation from which any other statement can be generated by means of the axioms; the cardinality of this set is taken to indicate the complexity of the relation. Building upon the idea of dominance, we introduce the concept of stability to provide for a more compact representation of independence. We give an associated algorithm for establishing such a representation.We show that, with our concept of stability, many independence relations are found to be of lower complexity than with existing representations.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:45:20 GMT" } ]
1,342,656,000,000
[ [ "de Waal", "Peter", "" ], [ "van der Gaag", "Linda C.", "" ] ]
1207.4121
Fabio Gagliardi Cozman
Fabio Gagliardi Cozman, Cassio Polpo de Campos, Jaime Ide, Jose Carlos Ferreira da Rocha
Propositional and Relational Bayesian Networks Associated with Imprecise and Qualitative Probabilistic Assesments
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-104-111
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper investigates a representation language with flexibility inspired by probabilistic logic and compactness inspired by relational Bayesian networks. The goal is to handle propositional and first-order constructs together with precise, imprecise, indeterminate and qualitative probabilistic assessments. The paper shows how this can be achieved through the theory of credal networks. New exact and approximate inference algorithms based on multilinear programming and iterated/loopy propagation of interval probabilities are presented; their superior performance, compared to existing ones, is shown empirically.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:45:39 GMT" } ]
1,342,656,000,000
[ [ "Cozman", "Fabio Gagliardi", "" ], [ "de Campos", "Cassio Polpo", "" ], [ "Ide", "Jaime", "" ], [ "da Rocha", "Jose Carlos Ferreira", "" ] ]
1207.4123
Carlos Chesnevar
Carlos Chesnevar, Guillermo Simari, Teresa Alsinet, Lluis Godo
A Logic Programming Framework for Possibilistic Argumentation with Vague Knowledge
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-76-84
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Defeasible argumentation frameworks have evolved to become a sound setting to formalize commonsense, qualitative reasoning from incomplete and potentially inconsistent knowledge. Defeasible Logic Programming (DeLP) is a defeasible argumentation formalism based on an extension of logic programming. Although DeLP has been successfully integrated in a number of different real-world applications, DeLP cannot deal with explicit uncertainty, nor with vague knowledge, as defeasibility is directly encoded in the object language. This paper introduces P-DeLP, a new logic programming language that extends original DeLP capabilities for qualitative reasoning by incorporating the treatment of possibilistic uncertainty and fuzzy knowledge. Such features will be formalized on the basis of PGL, a possibilistic logic based on Godel fuzzy logic.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:46:10 GMT" } ]
1,342,656,000,000
[ [ "Chesnevar", "Carlos", "" ], [ "Simari", "Guillermo", "" ], [ "Alsinet", "Teresa", "" ], [ "Godo", "Lluis", "" ] ]
1207.4124
Hei Chan
Hei Chan, Adnan Darwiche
Sensitivity Analysis in Bayesian Networks: From Single to Multiple Parameters
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-67-75
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Previous work on sensitivity analysis in Bayesian networks has focused on single parameters, where the goal is to understand the sensitivity of queries to single parameter changes, and to identify single parameter changes that would enforce a certain query constraint. In this paper, we expand the work to multiple parameters which may be in the CPT of a single variable, or the CPTs of multiple variables. Not only do we identify the solution space of multiple parameter changes that would be needed to enforce a query constraint, but we also show how to find the optimal solution, that is, the one which disturbs the current probability distribution the least (with respect to a specific measure of disturbance). We characterize the computational complexity of our new techniques and discuss their applications to developing and debugging Bayesian networks, and to the problem of reasoning about the value (reliability) of new information.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:46:27 GMT" } ]
1,342,656,000,000
[ [ "Chan", "Hei", "" ], [ "Darwiche", "Adnan", "" ] ]
1207.4126
Ronen I. Brafman
Ronen I. Brafman, Carmel Domshlak, Tanya Kogan
Compact Value-Function Representations for Qualitative Preferences
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-51-59
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the challenge of preference elicitation in systems that help users discover the most desirable item(s) within a given database. Past work on preference elicitation focused on structured models that provide a factored representation of users' preferences. Such models require less information to construct and support efficient reasoning algorithms. This paper makes two substantial contributions to this area: (1) Strong representation theorems for factored value functions. (2) A methodology that utilizes our representation results to address the problem of optimal item selection.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:47:08 GMT" } ]
1,342,656,000,000
[ [ "Brafman", "Ronen I.", "" ], [ "Domshlak", "Carmel", "" ], [ "Kogan", "Tanya", "" ] ]
1207.4130
Leila Amgoud
Leila Amgoud, Henri Prade
Using arguments for making decisions: A possibilistic logic approach
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-10-17
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Humans currently use arguments for explaining choices which are already made, or for evaluating potential choices. Each potential choice has usually pros and cons of various strengths. In spite of the usefulness of arguments in a decision making process, there have been few formal proposals handling this idea if we except works by Fox and Parsons and by Bonet and Geffner. In this paper we propose a possibilistic logic framework where arguments are built from an uncertain knowledge base and a set of prioritized goals. The proposed approach can compute two kinds of decisions by distinguishing between pessimistic and optimistic attitudes. When the available, maybe uncertain, knowledge is consistent, as well as the set of prioritized goals (which have to be fulfilled as far as possible), the method for evaluating decisions on the basis of arguments agrees with the possibility theory-based approach to decision-making under uncertainty. Taking advantage of its relation with formal approaches to defeasible argumentation, the proposed framework can be generalized in case of partially inconsistent knowledge, or goal bases.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:48:33 GMT" } ]
1,342,656,000,000
[ [ "Amgoud", "Leila", "" ], [ "Prade", "Henri", "" ] ]
1207.4135
David A. McAllester
David A. McAllester, Michael Collins, Fernando Pereira
Case-Factor Diagrams for Structured Probabilistic Modeling
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-382-391
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a probabilistic formalism subsuming Markov random fields of bounded tree width and probabilistic context free grammars. Our models are based on a representation of Boolean formulas that we call case-factor diagrams (CFDs). CFDs are similar to binary decision diagrams (BDDs) but are concise for circuits of bounded tree width (unlike BDDs) and can concisely represent the set of parse trees over a given string undera given context free grammar (also unlike BDDs). A probabilistic model consists of aCFD defining a feasible set of Boolean assignments and a weight (or cost) for each individual Boolean variable. We give an insideoutside algorithm for simultaneously computing the marginal of each Boolean variable, and a Viterbi algorithm for finding the mininum cost variable assignment. Both algorithms run in time proportional to the size of the CFD.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:52:02 GMT" } ]
1,342,656,000,000
[ [ "McAllester", "David A.", "" ], [ "Collins", "Michael", "" ], [ "Pereira", "Fernando", "" ] ]
1207.4136
Yongyi Mao
Yongyi Mao, Frank Kschischang, Brendan J. Frey
Convolutional Factor Graphs as Probabilistic Models
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-374-381
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Based on a recent development in the area of error control coding, we introduce the notion of convolutional factor graphs (CFGs) as a new class of probabilistic graphical models. In this context, the conventional factor graphs are referred to as multiplicative factor graphs (MFGs). This paper shows that CFGs are natural models for probability functions when summation of independent latent random variables is involved. In particular, CFGs capture a large class of linear models, where the linearity is in the sense that the observed variables are obtained as a linear ransformation of the latent variables taking arbitrary distributions. We use Gaussian models and independent factor models as examples to emonstrate the use of CFGs. The requirement of a linear transformation between latent variables (with certain independence restriction) and the bserved variables, to an extent, limits the modelling flexibility of CFGs. This structural restriction however provides a powerful analytic tool to the framework of CFGs; that is, upon taking the Fourier transform of the function represented by the CFG, the resulting function is represented by a FG with identical structure. This Fourier transform duality allows inference problems on a CFG to be solved on the corresponding dual MFG.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:52:18 GMT" } ]
1,342,656,000,000
[ [ "Mao", "Yongyi", "" ], [ "Kschischang", "Frank", "" ], [ "Frey", "Brendan J.", "" ] ]
1207.4137
Anders L. Madsen
Anders L. Madsen
An Empirical Evaluation of Possible Variations of Lazy Propagation
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-366-373
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As real-world Bayesian networks continue to grow larger and more complex, it is important to investigate the possibilities for improving the performance of existing algorithms of probabilistic inference. Motivated by examples, we investigate the dependency of the performance of Lazy propagation on the message computation algorithm. We show how Symbolic Probabilistic Inference (SPI) and Arc-Reversal (AR) can be used for computation of clique to clique messages in the addition to the traditional use of Variable Elimination (VE). In addition, the paper resents the results of an empirical evaluation of the performance of Lazy propagation using VE, SPI, and AR as the message computation algorithm. The results of the empirical evaluation show that for most networks, the performance of inference did not depend on the choice of message computation algorithm, but for some randomly generated networks the choice had an impact on both space and time performance. In the cases where the choice had an impact, AR produced the best results.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:52:35 GMT" } ]
1,342,656,000,000
[ [ "Madsen", "Anders L.", "" ] ]
1207.4150
Carlos E. Guestrin
Carlos E. Guestrin, Milos Hauskrecht, Branislav Kveton
Solving Factored MDPs with Continuous and Discrete Variables
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-235-242
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Although many real-world stochastic planning problems are more naturally formulated by hybrid models with both discrete and continuous variables, current state-of-the-art methods cannot adequately address these problems. We present the first framework that can exploit problem structure for modeling and solving hybrid problems efficiently. We formulate these problems as hybrid Markov decision processes (MDPs with continuous and discrete state and action variables), which we assume can be represented in a factored way using a hybrid dynamic Bayesian network (hybrid DBN). This formulation also allows us to apply our methods to collaborative multiagent settings. We present a new linear program approximation method that exploits the structure of the hybrid MDP and lets us compute approximate value functions more efficiently. In particular, we describe a new factored discretization of continuous variables that avoids the exponential blow-up of traditional approaches. We provide theoretical bounds on the quality of such an approximation and on its scale-up potential. We support our theoretical arguments with experiments on a set of control problems with up to 28-dimensional continuous state space and 22-dimensional action space.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:57:04 GMT" } ]
1,342,656,000,000
[ [ "Guestrin", "Carlos E.", "" ], [ "Hauskrecht", "Milos", "" ], [ "Kveton", "Branislav", "" ] ]
1207.4153
Changhe Yuan
Changhe Yuan, Tsai-Ching Lu, Marek J. Druzdzel
Annealed MAP
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-628-635
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Maximum a Posteriori assignment (MAP) is the problem of finding the most probable instantiation of a set of variables given the partial evidence on the other variables in a Bayesian network. MAP has been shown to be a NP-hard problem [22], even for constrained networks, such as polytrees [18]. Hence, previous approaches often fail to yield any results for MAP problems in large complex Bayesian networks. To address this problem, we propose AnnealedMAP algorithm, a simulated annealing-based MAP algorithm. The AnnealedMAP algorithm simulates a non-homogeneous Markov chain whose invariant function is a probability density that concentrates itself on the modes of the target density. We tested this algorithm on several real Bayesian networks. The results show that, while maintaining good quality of the MAP solutions, the AnnealedMAP algorithm is also able to solve many problems that are beyond the reach of previous approaches.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 14:59:29 GMT" } ]
1,342,656,000,000
[ [ "Yuan", "Changhe", "" ], [ "Lu", "Tsai-Ching", "" ], [ "Druzdzel", "Marek J.", "" ] ]
1207.4160
Linda C. van der Gaag
Linda C. van der Gaag, Hans L. Bodlaender, Ad Feelders
Monotonicity in Bayesian Networks
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-569-576
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For many real-life Bayesian networks, common knowledge dictates that the output established for the main variable of interest increases with higher values for the observable variables. We define two concepts of monotonicity to capture this type of knowledge. We say that a network is isotone in distribution if the probability distribution computed for the output variable given specific observations is stochastically dominated by any such distribution given higher-ordered observations; a network is isotone in mode if a probability distribution given higher observations has a higher mode. We show that establishing whether a network exhibits any of these properties of monotonicity is coNPPP-complete in general, and remains coNP-complete for polytrees. We present an approximate algorithm for deciding whether a network is monotone in distribution and illustrate its application to a real-life network in oncology.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 15:02:16 GMT" } ]
1,342,656,000,000
[ [ "van der Gaag", "Linda C.", "" ], [ "Bodlaender", "Hans L.", "" ], [ "Feelders", "Ad", "" ] ]
1207.4166
Trey Smith
Trey Smith, Reid Simmons
Heuristic Search Value Iteration for POMDPs
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-520-527
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a novel POMDP planning algorithm called heuristic search value iteration (HSVI).HSVI is an anytime algorithm that returns a policy and a provable bound on its regret with respect to the optimal policy. HSVI gets its power by combining two well-known techniques: attention-focusing search heuristics and piecewise linear convex representations of the value function. HSVI's soundness and convergence have been proven. On some benchmark problems from the literature, HSVI displays speedups of greater than 100 with respect to other state-of-the-art POMDP value iteration algorithms. We also apply HSVI to a new rover exploration problem 10 times larger than most POMDP problems in the literature.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 15:04:47 GMT" } ]
1,342,656,000,000
[ [ "Smith", "Trey", "" ], [ "Simmons", "Reid", "" ] ]
1207.4168
Lenhart Schubert
Lenhart Schubert
A New Characterization of Probabilities in Bayesian Networks
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-495-503
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We characterize probabilities in Bayesian networks in terms of algebraic expressions called quasi-probabilities. These are arrived at by casting Bayesian networks as noisy AND-OR-NOT networks, and viewing the subnetworks that lead to a node as arguments for or against a node. Quasi-probabilities are in a sense the "natural" algebra of Bayesian networks: we can easily compute the marginal quasi-probability of any node recursively, in a compact form; and we can obtain the joint quasi-probability of any set of nodes by multiplying their marginals (using an idempotent product operator). Quasi-probabilities are easily manipulated to improve the efficiency of probabilistic inference. They also turn out to be representable as square-wave pulse trains, and joint and marginal distributions can be computed by multiplication and complementation of pulse trains.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 15:05:36 GMT" } ]
1,342,656,000,000
[ [ "Schubert", "Lenhart", "" ] ]
1207.4170
Silja Renooij
Silja Renooij, Linda C. van der Gaag
Evidence-invariant Sensitivity Bounds
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-479-486
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The sensitivities revealed by a sensitivity analysis of a probabilistic network typically depend on the entered evidence. For a real-life network therefore, the analysis is performed a number of times, with different evidence. Although efficient algorithms for sensitivity analysis exist, a complete analysis is often infeasible because of the large range of possible combinations of observations. In this paper we present a method for studying sensitivities that are invariant to the evidence entered. Our method builds upon the idea of establishing bounds between which a parameter can be varied without ever inducing a change in the most likely value of a variable of interest.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 15:06:14 GMT" } ]
1,342,656,000,000
[ [ "Renooij", "Silja", "" ], [ "van der Gaag", "Linda C.", "" ] ]
1207.4175
Alon Orlitsky
Alon Orlitsky, Narayana Santhanam, Krishnamurthy Viswanathan, Junan Zhang
On Modeling Profiles instead of Values
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-426-435
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of estimating the distribution underlying an observed sample of data. Instead of maximum likelihood, which maximizes the probability of the ob served values, we propose a different estimate, the high-profile distribution, which maximizes the probability of the observed profile the number of symbols appearing any given number of times. We determine the high-profile distribution of several data samples, establish some of its general properties, and show that when the number of distinct symbols observed is small compared to the data size, the high-profile and maximum-likelihood distributions are roughly the same, but when the number of symbols is large, the distributions differ, and high-profile better explains the data.
[ { "version": "v1", "created": "Wed, 11 Jul 2012 15:10:15 GMT" } ]
1,342,656,000,000
[ [ "Orlitsky", "Alon", "" ], [ "Santhanam", "Narayana", "" ], [ "Viswanathan", "Krishnamurthy", "" ], [ "Zhang", "Junan", "" ] ]
1207.4176
Valentina Bayer-Zubek
Valentina Bayer-Zubek
Learning Diagnostic Policies from Examples by Systematic Search
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-27-34
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A diagnostic policy specifies what test to perform next, based on the results of previous tests, and when to stop and make a diagnosis. Cost-sensitive diagnostic policies perform tradeoffs between (a) the cost of tests and (b) the cost of misdiagnoses. An optimal diagnostic policy minimizes the expected total cost. We formalize this diagnosis process as a Markov Decision Process (MDP). We investigate two types of algorithms for solving this MDP: systematic search based on AO* algorithm and greedy search (particularly the Value of Information method). We investigate the issue of learning the MDP probabilities from examples, but only as they are relevant to the search for good policies. We do not learn nor assume a Bayesian network for the diagnosis process. Regularizers are developed to control overfitting and speed up the search. This research is the first that integrates overfitting prevention into systematic search. The paper has two contributions: it discusses the factors that make systematic search feasible for diagnosis, and it shows experimentally, on benchmark data sets, that systematic search methods produce better diagnostic policies than greedy methods.
[ { "version": "v1", "created": "Thu, 12 Jul 2012 19:44:39 GMT" } ]
1,342,656,000,000
[ [ "Bayer-Zubek", "Valentina", "" ] ]
1207.4177
Barry Cobb
Barry Cobb, Prakash P. Shenoy
Hybrid Influence Diagrams Using Mixtures of Truncated Exponentials
Appears in Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (UAI2004)
null
null
UAI-P-2004-PG-85-93
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mixtures of truncated exponentials (MTE) potentials are an alternative to discretization for representing continuous chance variables in influence diagrams. Also, MTE potentials can be used to approximate utility functions. This paper introduces MTE influence diagrams, which can represent decision problems without restrictions on the relationships between continuous and discrete chance variables, without limitations on the distributions of continuous chance variables, and without limitations on the nature of the utility functions. In MTE influence diagrams, all probability distributions and the joint utility function (or its multiplicative factors) are represented by MTE potentials and decision nodes are assumed to have discrete state spaces. MTE influence diagrams are solved by variable elimination using a fusion algorithm.
[ { "version": "v1", "created": "Thu, 12 Jul 2012 19:45:33 GMT" } ]
1,342,656,000,000
[ [ "Cobb", "Barry", "" ], [ "Shenoy", "Prakash P.", "" ] ]
1207.4432
Vesna Marinkovi\'c
Vesna Marinkovic, Predrag Janicic
Towards Understanding Triangle Construction Problems
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Straightedge and compass construction problems are one of the oldest and most challenging problems in elementary mathematics. The central challenge, for a human or for a computer program, in solving construction problems is a huge search space. In this paper we analyze one family of triangle construction problems, aiming at detecting a small core of the underlying geometry knowledge. The analysis leads to a small set of needed definitions, lemmas and primitive construction steps, and consequently, to a simple algorithm for automated solving of problems from this family. The same approach can be applied to other families of construction problems.
[ { "version": "v1", "created": "Wed, 18 Jul 2012 18:17:14 GMT" } ]
1,342,656,000,000
[ [ "Marinkovic", "Vesna", "" ], [ "Janicic", "Predrag", "" ] ]
1207.4708
Marc G. Bellemare
Marc G. Bellemare, Yavar Naddaf, Joel Veness, Michael Bowling
The Arcade Learning Environment: An Evaluation Platform for General Agents
null
Journal of Artificial Intelligence Research 47, pages 253-279
10.1613/jair.3912
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article we introduce the Arcade Learning Environment (ALE): both a challenge problem and a platform and methodology for evaluating the development of general, domain-independent AI technology. ALE provides an interface to hundreds of Atari 2600 game environments, each one different, interesting, and designed to be a challenge for human players. ALE presents significant research challenges for reinforcement learning, model learning, model-based planning, imitation learning, transfer learning, and intrinsic motivation. Most importantly, it provides a rigorous testbed for evaluating and comparing approaches to these problems. We illustrate the promise of ALE by developing and benchmarking domain-independent agents designed using well-established AI techniques for both reinforcement learning and planning. In doing so, we also propose an evaluation methodology made possible by ALE, reporting empirical results on over 55 different games. All of the software, including the benchmark agents, is publicly available.
[ { "version": "v1", "created": "Thu, 19 Jul 2012 15:33:25 GMT" }, { "version": "v2", "created": "Fri, 21 Jun 2013 18:07:06 GMT" } ]
1,372,032,000,000
[ [ "Bellemare", "Marc G.", "" ], [ "Naddaf", "Yavar", "" ], [ "Veness", "Joel", "" ], [ "Bowling", "Michael", "" ] ]
1207.4813
Ram\'on Pino P\'erez
Jos\'e Luis Chac\'on and Ram\'on Pino P\'erez
Exploring the rationality of some syntactic merging operators (extended version)
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most merging operators are defined by semantics methods which have very high computational complexity. In order to have operators with a lower computational complexity, some merging operators defined in a syntactical way have be proposed. In this work we define some syntactical merging operators and exploring its rationality properties. To do that we constrain the belief bases to be sets of formulas very close to logic programs and the underlying logic is defined through forward chaining rule (Modus Ponens). We propose two types of operators: arbitration operators when the inputs are only two bases and fusion with integrity constraints operators. We introduce a set of postulates inspired of postulates LS, proposed by Liberatore and Shaerf and then we analyzed the first class of operators through these postulates. We also introduce a set of postulates inspired of postulates KP, proposed by Konieczny and Pino P\'erez and then we analyzed the second class of operators through these postulates.
[ { "version": "v1", "created": "Thu, 19 Jul 2012 21:30:17 GMT" } ]
1,343,001,600,000
[ [ "Chacón", "José Luis", "" ], [ "Pérez", "Ramón Pino", "" ] ]
1207.5152
Fatih Korkmaz
Fatih Korkmaz, M. Faruk Cakir, Yilmaz Korkmaz, Ismail Topaloglu
Stator flux optimization on direct torque control with fuzzy logic
8 pages, 8 figures, Itca 2012 conference
null
10.5121/csit.2012.2355
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Direct Torque Control (DTC) is well known as an effective control technique for high performance drives in a wide variety of industrial applications and conventional DTC technique uses two constant reference value: torque and stator flux. In this paper, fuzzy logic based stator flux optimization technique for DTC drives that has been proposed. The proposed fuzzy logic based stator flux optimizer self-regulates the stator flux reference using induction motor load situation without need of any motor parameters. Simulation studies have been carried out with Matlab/Simulink to compare the proposed system behaviors at vary load conditions. Simulation results show that the performance of the proposed DTC technique has been improved and especially at low-load conditions torque ripple are greatly reduced with respect to the conventional DTC.
[ { "version": "v1", "created": "Sat, 21 Jul 2012 15:08:06 GMT" } ]
1,354,579,200,000
[ [ "Korkmaz", "Fatih", "" ], [ "Cakir", "M. Faruk", "" ], [ "Korkmaz", "Yilmaz", "" ], [ "Topaloglu", "Ismail", "" ] ]
1207.5879
David Tolpin
Nicholas Hay and Stuart Russell, David Tolpin and Solomon Eyal Shimony
Selecting Computations: Theory and Applications
10 pages, UAI 2012
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Sequential decision problems are often approximately solvable by simulating possible future action sequences. {\em Metalevel} decision procedures have been developed for selecting {\em which} action sequences to simulate, based on estimating the expected improvement in decision quality that would result from any particular simulation; an example is the recent work on using bandit algorithms to control Monte Carlo tree search in the game of Go. In this paper we develop a theoretical basis for metalevel decisions in the statistical framework of Bayesian {\em selection problems}, arguing (as others have done) that this is more appropriate than the bandit framework. We derive a number of basic results applicable to Monte Carlo selection problems, including the first finite sampling bounds for optimal policies in certain cases; we also provide a simple counterexample to the intuitive conjecture that an optimal policy will necessarily reach a decision in all cases. We then derive heuristic approximations in both Bayesian and distribution-free settings and demonstrate their superiority to bandit-based heuristics in one-shot decision problems and in Go.
[ { "version": "v1", "created": "Wed, 25 Jul 2012 03:31:08 GMT" } ]
1,343,260,800,000
[ [ "Hay", "Nicholas", "" ], [ "Russell", "Stuart", "" ], [ "Tolpin", "David", "" ], [ "Shimony", "Solomon Eyal", "" ] ]
1207.5926
Bart Demoen
Bart Demoen and Maria Garcia de la Banda
Redundant Sudoku Rules
14 pages, 161 figures, to appear in TPLP
Theory and Practice of Logic Programming 14 (2014) 363-377
10.1017/S1471068412000361
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The rules of Sudoku are often specified using twenty seven \texttt{all\_different} constraints, referred to as the {\em big} \mrules. Using graphical proofs and exploratory logic programming, the following main and new result is obtained: many subsets of six of these big \mrules are redundant (i.e., they are entailed by the remaining twenty one \mrules), and six is maximal (i.e., removing more than six \mrules is not possible while maintaining equivalence). The corresponding result for binary inequality constraints, referred to as the {\em small} \mrules, is stated as a conjecture.
[ { "version": "v1", "created": "Wed, 25 Jul 2012 08:57:20 GMT" } ]
1,582,070,400,000
[ [ "Demoen", "Bart", "" ], [ "de la Banda", "Maria Garcia", "" ] ]
1207.6514
Steven Prestwich
Steven Prestwich
Earthquake Scenario Reduction by Symmetry Reasoning
Abstract presented at EURO conference, Vilnius, Lithuania, 2012
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A recently identified problem is that of finding an optimal investment plan for a transportation network, given that a disaster such as an earthquake may destroy links in the network. The aim is to strengthen key links to preserve the expected network connectivity. A network based on the Istanbul highway system has thirty links and therefore a billion scenarios, but it has been estimated that sampling a million scenarios gives reasonable accuracy. In this paper we use symmetry reasoning to reduce the number of scenarios to a much smaller number, making sampling unnecessary. This result can be used to facilitate metaheuristic and exact approaches to the problem.
[ { "version": "v1", "created": "Fri, 27 Jul 2012 11:14:23 GMT" } ]
1,343,606,400,000
[ [ "Prestwich", "Steven", "" ] ]
1207.6713
Hankz Hankui Zhuo
Hankz Hankui Zhuo, Subbarao Kambhampati, and Tuan Nguyen
Model-Lite Case-Based Planning
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
There is increasing awareness in the planning community that depending on complete models impedes the applicability of planning technology in many real world domains where the burden of specifying complete domain models is too high. In this paper, we consider a novel solution for this challenge that combines generative planning on incomplete domain models with a library of plan cases that are known to be correct. While this was arguably the original motivation for case-based planning, most existing case-based planners assume (and depend on) from-scratch planners that work on complete domain models. In contrast, our approach views the plan generated with respect to the incomplete model as a "skeletal plan" and augments it with directed mining of plan fragments from library cases. We will present the details of our approach and present an empirical evaluation of our method in comparison to a state-of-the-art case-based planner that depends on complete domain models.
[ { "version": "v1", "created": "Sat, 28 Jul 2012 17:00:01 GMT" } ]
1,343,692,800,000
[ [ "Zhuo", "Hankz Hankui", "" ], [ "Kambhampati", "Subbarao", "" ], [ "Nguyen", "Tuan", "" ] ]
1208.1743
Amir Noori
Amir Noori, Mohammad Bagher Menhaj, Masoud Shafiee
Hybrid systems modeling for gas transmission network
This paper has been withdrawn by the author due to a crucial citation error in introduction section
The 4th IFAC Conference on Management and Control of Production and Logistics, 2007
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gas Transmission Networks are large-scale complex systems, and corresponding design and control problems are challenging. In this paper, we consider the problem of control and management of these systems in crisis situations. We present these networks by a hybrid systems framework that provides required analysis models. Further, we discuss decision-making using computational discrete and hybrid optimization methods. In particular, several reinforcement learning methods are employed to explore decision space and achieve the best policy in a specific crisis situation. Simulations are presented to illustrate the efficiency of the method.
[ { "version": "v1", "created": "Wed, 8 Aug 2012 19:24:08 GMT" }, { "version": "v2", "created": "Sat, 22 Sep 2012 20:03:41 GMT" }, { "version": "v3", "created": "Tue, 25 Sep 2012 16:00:02 GMT" }, { "version": "v4", "created": "Fri, 28 Sep 2012 07:07:55 GMT" } ]
1,349,049,600,000
[ [ "Noori", "Amir", "" ], [ "Menhaj", "Mohammad Bagher", "" ], [ "Shafiee", "Masoud", "" ] ]
1208.1955
Fahimeh Farahbod
Fahimeh Farahbod and Mahdi Eftekhari
Comparison of different T-norm operators in classification problems
6 pages, 1 figure, 4 tables; International Journal of Fuzzy Logic Systems (IJFLS) Vol.2, No.3, July 2012
null
10.5121/ijfls.2012.2303
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fuzzy rule based classification systems are one of the most popular fuzzy modeling systems used in pattern classification problems. This paper investigates the effect of applying nine different T-norms in fuzzy rule based classification systems. In the recent researches, fuzzy versions of confidence and support merits from the field of data mining have been widely used for both rules selecting and weighting in the construction of fuzzy rule based classification systems. For calculating these merits the product has been usually used as a T-norm. In this paper different T-norms have been used for calculating the confidence and support measures. Therefore, the calculations in rule selection and rule weighting steps (in the process of constructing the fuzzy rule based classification systems) are modified by employing these T-norms. Consequently, these changes in calculation results in altering the overall accuracy of rule based classification systems. Experimental results obtained on some well-known data sets show that the best performance is produced by employing the Aczel-Alsina operator in terms of the classification accuracy, the second best operator is Dubois-Prade and the third best operator is Dombi. In experiments, we have used 12 data sets with numerical attributes from the University of California, Irvine machine learning repository (UCI).
[ { "version": "v1", "created": "Thu, 9 Aug 2012 15:41:27 GMT" } ]
1,344,556,800,000
[ [ "Farahbod", "Fahimeh", "" ], [ "Eftekhari", "Mahdi", "" ] ]
1208.2102
Abdul Kareem
Abdul Kareem, Mohammad Fazle Azeem
A Novel Fuzzy Logic Based Adaptive Supertwisting Sliding Mode Control Algorithm for Dynamic Uncertain Systems
14 pages
International Journal of Artificial Intelligence & Applications (IJAIA), Vol.3, No.4, July 2012, 21-34
10.5121/ijaia.2012.3402
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents a novel fuzzy logic based Adaptive Super-twisting Sliding Mode Controller for the control of dynamic uncertain systems. The proposed controller combines the advantages of Second order Sliding Mode Control, Fuzzy Logic Control and Adaptive Control. The reaching conditions, stability and robustness of the system with the proposed controller are guaranteed. In addition, the proposed controller is well suited for simple design and implementation. The effectiveness of the proposed controller over the first order Sliding Mode Fuzzy Logic controller is illustrated by Matlab based simulations performed on a DC-DC Buck converter. Based on this comparison, the proposed controller is shown to obtain the desired transient response without causing chattering and error under steady-state conditions. The proposed controller is able to give robust performance in terms of rejection to input voltage variations and load variations.
[ { "version": "v1", "created": "Fri, 10 Aug 2012 07:19:48 GMT" } ]
1,344,816,000,000
[ [ "Kareem", "Abdul", "" ], [ "Azeem", "Mohammad Fazle", "" ] ]
1208.2199
Mohammad Havaei
Mohammad Havaei, Nandivada Krishna Prasad, and Velleshala Sudheer
Elimination of ISI Using Improved LMS Based Decision Feedback Equalizer
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper deals with the implementation of Least Mean Square (LMS) algorithm in Decision Feedback Equalizer (DFE) for removal of Inter Symbol Interference (ISI) at the receiver. The channel disrupts the transmitted signal by spreading it in time. Although, the LMS algorithm is robust and reliable, it is slow in convergence. In order to increase the speed of convergence, modifications have been made in the algorithm where the weights get updated depending on the severity of disturbance.
[ { "version": "v1", "created": "Fri, 10 Aug 2012 15:05:38 GMT" } ]
1,344,816,000,000
[ [ "Havaei", "Mohammad", "" ], [ "Prasad", "Nandivada Krishna", "" ], [ "Sudheer", "Velleshala", "" ] ]
1208.2566
Sebastian Ordyniak
Christer Baeckstroem, Yue Chen, Peter Jonsson, Sebastian Ordyniak, Stefan Szeider
The Complexity of Planning Revisited - A Parameterized Analysis
(author's self-archived copy)
Proc. AAAI'12 (AAAI Press 2012) pp. 1735-1741
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The early classifications of the computational complexity of planning under various restrictions in STRIPS (Bylander) and SAS+ (Baeckstroem and Nebel) have influenced following research in planning in many ways. We go back and reanalyse their subclasses, but this time using the more modern tool of parameterized complexity analysis. This provides new results that together with the old results give a more detailed picture of the complexity landscape. We demonstrate separation results not possible with standard complexity theory, which contributes to explaining why certain cases of planning have seemed simpler in practice than theory has predicted. In particular, we show that certain restrictions of practical interest are tractable in the parameterized sense of the term, and that a simple heuristic is sufficient to make a well-known partial-order planner exploit this fact.
[ { "version": "v1", "created": "Mon, 13 Aug 2012 12:40:44 GMT" } ]
1,344,902,400,000
[ [ "Baeckstroem", "Christer", "" ], [ "Chen", "Yue", "" ], [ "Jonsson", "Peter", "" ], [ "Ordyniak", "Sebastian", "" ], [ "Szeider", "Stefan", "" ] ]
1208.3015
Andreas Schutt
Andreas Schutt and Thibaut Feydy and Peter J. Stuckey
Explaining Time-Table-Edge-Finding Propagation for the Cumulative Resource Constraint
22 pages, 3 figures, 11 tables, 2 algorithms
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Cumulative resource constraints can model scarce resources in scheduling problems or a dimension in packing and cutting problems. In order to efficiently solve such problems with a constraint programming solver, it is important to have strong and fast propagators for cumulative resource constraints. One such propagator is the recently developed time-table-edge-finding propagator, which considers the current resource profile during the edge-finding propagation. Recently, lazy clause generation solvers, i.e. constraint programming solvers incorporating nogood learning, have proved to be excellent at solving scheduling and cutting problems. For such solvers, concise and accurate explanations of the reasons for propagation are essential for strong nogood learning. In this paper, we develop the first explaining version of time-table-edge-finding propagation and show preliminary results on resource-constrained project scheduling problems from various standard benchmark suites. On the standard benchmark suite PSPLib, we were able to close one open instance and to improve the lower bound of about 60% of the remaining open instances. Moreover, 6 of those instances were closed.
[ { "version": "v1", "created": "Wed, 15 Aug 2012 02:17:55 GMT" }, { "version": "v2", "created": "Mon, 10 Sep 2012 05:52:51 GMT" } ]
1,347,321,600,000
[ [ "Schutt", "Andreas", "" ], [ "Feydy", "Thibaut", "" ], [ "Stuckey", "Peter J.", "" ] ]
1208.3148
Ernesto Jim\'enez-Ruiz
Christian Meilicke (1), Ondrej Sv\'ab-Zamazal (2), C\'assia Trojahn (3), Ernesto Jim\'enez-Ruiz (4), Jos\'e-Luis Aguirre (3), Heiner Stuckenschmidt (1), Bernardo Cuenca Grau (4) ((1) University of Mannheim, (2) University of Economics Prague, (3) INRIA and LIG Grenoble, (4) University of Oxford)
Evaluating Ontology Matching Systems on Large, Multilingual and Real-world Test Cases
Technical Report of the OAEI 2011.5 Evaluation Campaign
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the field of ontology matching, the most systematic evaluation of matching systems is established by the Ontology Alignment Evaluation Initiative (OAEI), which is an annual campaign for evaluating ontology matching systems organized by different groups of researchers. In this paper, we report on the results of an intermediary OAEI campaign called OAEI 2011.5. The evaluations of this campaign are divided in five tracks. Three of these tracks are new or have been improved compared to previous OAEI campaigns. Overall, we evaluated 18 matching systems. We discuss lessons learned, in terms of scalability, multilingual issues and the ability do deal with real world cases from different domains.
[ { "version": "v1", "created": "Wed, 15 Aug 2012 15:46:31 GMT" } ]
1,345,075,200,000
[ [ "Meilicke", "Christian", "" ], [ "Sváb-Zamazal", "Ondrej", "" ], [ "Trojahn", "Cássia", "" ], [ "Jiménez-Ruiz", "Ernesto", "" ], [ "Aguirre", "José-Luis", "" ], [ "Stuckenschmidt", "Heiner", "" ], [ "Grau", "Bernardo Cuenca", "" ] ]
1208.3802
Nisheeth Joshi
Archana Vashisth, Iti Mathur, Nisheeth Joshi
OntoAna: Domain Ontology for Human Anatomy
Proceedings of 5th CSI National Conference on Education and Research. Organized by Lingayay University, Faridabad. Sponsored by Computer Society of India and IEEE Delhi Chapter. Proceedings published by Lingayay University Press
null
null
null
cs.AI
http://creativecommons.org/licenses/by/3.0/
Today, we can find many search engines which provide us with information which is more operational in nature. None of the search engines provide domain specific information. This becomes very troublesome to a novice user who wishes to have information in a particular domain. In this paper, we have developed an ontology which can be used by a domain specific search engine. We have developed an ontology on human anatomy, which captures information regarding cardiovascular system, digestive system, skeleton and nervous system. This information can be used by people working in medical and health care domain.
[ { "version": "v1", "created": "Sun, 19 Aug 2012 02:44:42 GMT" } ]
1,345,507,200,000
[ [ "Vashisth", "Archana", "" ], [ "Mathur", "Iti", "" ], [ "Joshi", "Nisheeth", "" ] ]
1208.3809
Nima Taghipour
Nima Taghipour, Daan Fierens, Guy Van den Broeck, Jesse Davis, Hendrik Blockeel
Lifted Variable Elimination: A Novel Operator and Completeness Results
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Various methods for lifted probabilistic inference have been proposed, but our understanding of these methods and the relationships between them is still limited, compared to their propositional counterparts. The only existing theoretical characterization of lifting is for weighted first-order model counting (WFOMC), which was shown to be complete domain-lifted for the class of 2-logvar models. This paper makes two contributions to lifted variable elimination (LVE). First, we introduce a novel inference operator called group inversion. Second, we prove that LVE augmented with this operator is complete in the same sense as WFOMC.
[ { "version": "v1", "created": "Sun, 19 Aug 2012 04:55:25 GMT" }, { "version": "v2", "created": "Fri, 24 Aug 2012 18:10:37 GMT" } ]
1,346,025,600,000
[ [ "Taghipour", "Nima", "" ], [ "Fierens", "Daan", "" ], [ "Broeck", "Guy Van den", "" ], [ "Davis", "Jesse", "" ], [ "Blockeel", "Hendrik", "" ] ]
1208.4942
Cm Pintea
Camelia-M. Pintea
A Unifying Survey of Reinforced, Sensitive and Stigmergic Agent-Based Approaches for E-GTSP
9 pages, 2 figures
Informatica. 26(3) (2015). 509-522
10.15388/Informatica.2015.61
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Generalized Traveling Salesman Problem (GTSP) is one of the NP-hard combinatorial optimization problems. A variant of GTSP is E-GTSP where E, meaning equality, has the constraint: exactly one node from a cluster of a graph partition is visited. The main objective of the E-GTSP is to find a minimum cost tour passing through exactly one node from each cluster of an undirected graph. Agent-based approaches involving are successfully used nowadays for solving real life complex problems. The aim of the current paper is to illustrate some variants of agent-based algorithms including ant-based models with specific properties for solving E-GTSP.
[ { "version": "v1", "created": "Fri, 24 Aug 2012 10:23:37 GMT" }, { "version": "v2", "created": "Thu, 13 Feb 2014 11:02:59 GMT" } ]
1,615,852,800,000
[ [ "Pintea", "Camelia-M.", "" ] ]
1208.4945
Cm Pintea
Camelia-M. Pintea, Gloria Cerasela Crisan, Mihai Manea
Parallel ACO with a Ring Neighborhood for Dynamic TSP
8 pages, 1 figure; accepted J. Information Technology Research
J Information Technology Research 5(4): 1-13 (2012)
10.4018/jitr.2012100101
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The current paper introduces a new parallel computing technique based on ant colony optimization for a dynamic routing problem. In the dynamic traveling salesman problem the distances between cities as travel times are no longer fixed. The new technique uses a parallel model for a problem variant that allows a slight movement of nodes within their Neighborhoods. The algorithm is tested with success on several large data sets.
[ { "version": "v1", "created": "Fri, 24 Aug 2012 10:38:49 GMT" }, { "version": "v2", "created": "Wed, 10 Oct 2012 13:14:13 GMT" } ]
1,595,894,400,000
[ [ "Pintea", "Camelia-M.", "" ], [ "Crisan", "Gloria Cerasela", "" ], [ "Manea", "Mihai", "" ] ]
1208.5154
David McAllester
David McAllester, Petri Myllymaki
Proceedings of the Twenty-Fourth Conference on Uncertainty in Artificial Intelligence (2008)
null
null
null
UAI2008
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is the Proceedings of the Twenty-Fourth Conference on Uncertainty in Artificial Intelligence, which was held in Helsinki, Finland, July 9 - 12 2008.
[ { "version": "v1", "created": "Sat, 25 Aug 2012 18:22:17 GMT" }, { "version": "v2", "created": "Thu, 28 Aug 2014 04:25:59 GMT" } ]
1,409,270,400,000
[ [ "McAllester", "David", "" ], [ "Myllymaki", "Petri", "" ] ]
1208.5155
Ronald Parr
Ronald Parr, Linda S. van der Gaag
Proceedings of the Twenty-Third Conference on Uncertainty in Artificial Intelligence (2007)
null
null
null
UAI2007
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is the Proceedings of the Twenty-Third Conference on Uncertainty in Artificial Intelligence, which was held in Vancouver, British Columbia, July 19 - 22 2007.
[ { "version": "v1", "created": "Sat, 25 Aug 2012 18:26:04 GMT" }, { "version": "v2", "created": "Thu, 28 Aug 2014 04:24:43 GMT" } ]
1,409,270,400,000
[ [ "Parr", "Ronald", "" ], [ "van der Gaag", "Linda S.", "" ] ]
1208.5159
Fahiem Bacchus
Fahiem Bacchus, Tommi Jaakkola
Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence (2005)
null
null
null
UAI2005
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is the Proceedings of the Twenty-First Conference on Uncertainty in Artificial Intelligence, which was held in Edinburgh, Scotland July 26 - 29 2005.
[ { "version": "v1", "created": "Sat, 25 Aug 2012 18:44:38 GMT" }, { "version": "v2", "created": "Thu, 28 Aug 2014 04:22:02 GMT" } ]
1,409,270,400,000
[ [ "Bacchus", "Fahiem", "" ], [ "Jaakkola", "Tommi", "" ] ]
1208.5160
Rina Dechter
Rina Dechter, Thomas S. Richardson
Proceedings of the Twenty-Second Conference on Uncertainty in Artificial Intelligence (2006)
null
null
null
UAI2006
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is the Proceedings of the Twenty-Second Conference on Uncertainty in Artificial Intelligence, which was held in Cambridge, MA, July 13 - 16 2006.
[ { "version": "v1", "created": "Sat, 25 Aug 2012 18:45:05 GMT" }, { "version": "v2", "created": "Thu, 28 Aug 2014 04:23:23 GMT" } ]
1,409,270,400,000
[ [ "Dechter", "Rina", "" ], [ "Richardson", "Thomas S.", "" ] ]
1208.5161
Max Chickering
Max Chickering, Joseph Halpern
Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence (2004)
null
null
null
UAI2004
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is the Proceedings of the Twentieth Conference on Uncertainty in Artificial Intelligence, which was held in Banff, Canada, July 7 - 11 2004.
[ { "version": "v1", "created": "Sat, 25 Aug 2012 18:48:34 GMT" }, { "version": "v2", "created": "Thu, 28 Aug 2014 04:20:22 GMT" } ]
1,409,270,400,000
[ [ "Chickering", "Max", "" ], [ "Halpern", "Joseph", "" ] ]
1208.5373
Cm Pintea
Camelia-M. Pintea, D. Dumitrescu
Distributed Pharaoh System for Network Routing
4 pages, 4 figures
Automat. Comput. Appl. Math. 16(1-2) (2007) 27-34
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper it is introduced a biobjective ant algorithm for constructing low cost routing networks. The new algorithm is called the Distributed Pharaoh System (DPS). DPS is based on AntNet algorithm. The algorithm is using Pharaoh Ant System (PAS) with an extra-exploration phase and a 'no-entry' condition in order to improve the solutions for the Low Cost Network Routing problem. Additionally it is used a cost model for overlay network construction that includes network traffic demands. The Pharaoh ants (Monomorium pharaonis) includes negative pheromones with signals concentrated at decision points where trails fork. The negative pheromones may complement positive pheromone or could help ants to escape from an unnecessarily long route to food that is being reinforced by attractive signals. Numerical experiments were made for a random 10-node network. The average node degree of the network tested was 4.0. The results are encouraging. The algorithm converges to the shortest path while converging on a low cost overlay routing network topology.
[ { "version": "v1", "created": "Mon, 27 Aug 2012 12:35:29 GMT" } ]
1,346,112,000,000
[ [ "Pintea", "Camelia-M.", "" ], [ "Dumitrescu", "D.", "" ] ]
1208.5554
Cm Pintea
Gabriela Czibula, Gloria Cerasela Crisan, Camelia-M. Pintea, Istvan-Gergely Czibula
Soft Computing approaches on the Bandwidth Problem
6 pages, 1 figure; accepted to Informatica
INFORMATICA 24(2):169-180 (2013)
10.15388/Informatica.2013.390
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Matrix Bandwidth Minimization Problem (MBMP) seeks for a simultaneous reordering of the rows and the columns of a square matrix such that the nonzero entries are collected within a band of small width close to the main diagonal. The MBMP is a NP-complete problem, with applications in many scientific domains, linear systems, artificial intelligence, and real-life situations in industry, logistics, information recovery. The complex problems are hard to solve, that is why any attempt to improve their solutions is beneficent. Genetic algorithms and ant-based systems are Soft Computing methods used in this paper in order to solve some MBMP instances. Our approach is based on a learning agent-based model involving a local search procedure. The algorithm is compared with the classical Cuthill-McKee algorithm, and with a hybrid genetic algorithm, using several instances from Matrix Market collection. Computational experiments confirm a good performance of the proposed algorithms for the considered set of MBMP instances. On Soft Computing basis, we also propose a new theoretical Reinforcement Learning model for solving the MBMP problem.
[ { "version": "v1", "created": "Tue, 28 Aug 2012 04:26:35 GMT" } ]
1,595,894,400,000
[ [ "Czibula", "Gabriela", "" ], [ "Crisan", "Gloria Cerasela", "" ], [ "Pintea", "Camelia-M.", "" ], [ "Czibula", "Istvan-Gergely", "" ] ]
1209.0852
Ehsan Saboori Mr.
Ehsan Saboori, Shafigh Parsazad, Yasaman Sanatkhani
Automatic firewall rules generator for anomaly detection systems with Apriori algorithm
4 Pages
2010 3rd International Conference on Advanced Computer Theory and Engineering (ICACTE), vol.6, no., pp.V6-57-V6-60, 2010
10.1109/ICACTE.2010.5579365
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Network intrusion detection systems have become a crucial issue for computer systems security infrastructures. Different methods and algorithms are developed and proposed in recent years to improve intrusion detection systems. The most important issue in current systems is that they are poor at detecting novel anomaly attacks. These kinds of attacks refer to any action that significantly deviates from the normal behaviour which is considered intrusion. This paper proposed a model to improve this problem based on data mining techniques. Apriori algorithm is used to predict novel attacks and generate real-time rules for firewall. Apriori algorithm extracts interesting correlation relationships among large set of data items. This paper illustrates how to use Apriori algorithm in intrusion detection systems to cerate a automatic firewall rules generator to detect novel anomaly attack. Apriori is the best-known algorithm to mine association rules. This is an innovative way to find association rules on large scale.
[ { "version": "v1", "created": "Wed, 5 Sep 2012 02:58:13 GMT" } ]
1,346,889,600,000
[ [ "Saboori", "Ehsan", "" ], [ "Parsazad", "Shafigh", "" ], [ "Sanatkhani", "Yasaman", "" ] ]
1209.0880
Christian Blum
Christian Blum and Verena Schmid and Lukas Baumgartner
On Solving the Oriented Two-Dimensional Bin Packing Problem under Free Guillotine Cutting: Exploiting the Power of Probabilistic Solution Construction
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Two-dimensional bin packing problems are highly relevant combinatorial optimization problems. They find a large number of applications, for example, in the context of transportation or warehousing, and for the cutting of different materials such as glass, wood or metal. In this work we deal with the oriented two-dimensional bin packing problem under free guillotine cutting. In this specific problem a set of oriented rectangular items is given which must be packed into a minimum number of bins of equal size. The first algorithm proposed in this work is a randomized multi-start version of a constructive one-pass heuristic from the literature. Additionally we propose the use of this randomized one-pass heuristic within an evolutionary algorithm. The results of the two proposed algorithms are compared to the best approaches from the literature. In particular the evolutionary algorithm compares very favorably to current state-of-the-art approaches. The optimal solution for 4 previously unsolved instances could be found.
[ { "version": "v1", "created": "Wed, 5 Sep 2012 07:38:58 GMT" } ]
1,346,889,600,000
[ [ "Blum", "Christian", "" ], [ "Schmid", "Verena", "" ], [ "Baumgartner", "Lukas", "" ] ]