The Experts below are selected from a list of 5805 Experts worldwide ranked by ideXlab platform
Peter Stone - One of the best experts on this subject based on the ideXlab platform.
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structure learning in ergodic factored mdps without knowledge of the transition function s in degree
International Conference on Machine Learning, 2011Co-Authors: Doran Chakraborty, Peter StoneAbstract:This paper introduces Learn Structure and Exploit Rmax (LSE-Rmax), a novel model based structure learning algorithm for ergodic factored-state MDPs. Given a planning horizon that satisfies a condition, LSE-Rmax provably guarantees a return very close to the optimal return, with a high certainty, without requiring any prior knowledge of the in-degree of the transition function as input. LSE-Rmax is fully implemented with a thorough analysis of its sample complexity. We also present empirical results demonstrating its effectiveness compared to prior approaches to the problem.
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ICML - Structure Learning in Ergodic Factored MDPs without Knowledge of the Transition Function's In-Degree
2011Co-Authors: Doran Chakraborty, Peter StoneAbstract:This paper introduces Learn Structure and Exploit Rmax (LSE-Rmax), a novel model based structure learning algorithm for ergodic factored-state MDPs. Given a planning horizon that satisfies a condition, LSE-Rmax provably guarantees a return very close to the optimal return, with a high certainty, without requiring any prior knowledge of the in-degree of the transition function as input. LSE-Rmax is fully implemented with a thorough analysis of its sample complexity. We also present empirical results demonstrating its effectiveness compared to prior approaches to the problem.
Nicholas K. Dulvy - One of the best experts on this subject based on the ideXlab platform.
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Maximum intrinsic rate of population increase in sharks, rays, and chimaeras: the importance of survival to maturity
2016Co-Authors: Sebastián A. Pardo, Holly K. Kindsvater, John D. Reynolds, Nicholas K. DulvyAbstract:The maximum intrinsic rate of population increase Rmax is a commonly estimated demographic parameter used in assessments of extinction risk. In teleosts, Rmax can be calculated using an estimate of spawners per spawner, but for chondrichthyans, most studies have used annual reproductive output b instead. This is problematic as it effectively assumes all juveniles survive to maturity. Here, we propose an updated Rmax equation that uses a simple mortality estimator which also accounts for survival to maturity: the reciprocal of average lifespan. For 94 chondrichthyans, we now estimate that Rmax values are on average 10% lower than previously published. Our updated Rmax estimates are lower than previously published for species that mature later relative to maximum age and those with high annual fecundity. The most extreme discrepancies in Rmax values occur in species with low age at maturity and low annual reproductive output. Our results indicate that chondrichthyans that mature relatively later in life, and to a lesser extent those that are highly fecund, are less resilient to fishing than previously thought.
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Maximum intrinsic rate of population increase in sharks, rays, and chimaeras: the importance of survival to maturity
Canadian Journal of Fisheries and Aquatic Sciences, 2016Co-Authors: Sebastián A. Pardo, Holly K. Kindsvater, John D. Reynolds, Nicholas K. DulvyAbstract:The maximum intrinsic rate of population increase (Rmax) is a commonly estimated demographic parameter used in assessments of extinction risk. In teleosts, Rmax can be calculated using an estimate of spawners per spawner, but for chondrichthyans, most studies have used annual reproductive output (b) instead. This is problematic as it effectively assumes all juveniles survive to maturity. Here, we propose an updated Rmax equation that uses a simple mortality estimator that also accounts for survival to maturity: the reciprocal of average life-span. For 94 chondrichthyans, we now estimate that Rmax values are on average 10% lower than previously published. Our updated Rmax estimates are lower than previously published for species that mature later relative to maximum age and those with high annual fecundity. The most extreme discrepancies in Rmax values occur in species with low age at maturity and low annual reproductive output. Our results indicate that chondrichthyans that mature relatively later in life...
Doran Chakraborty - One of the best experts on this subject based on the ideXlab platform.
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structure learning in ergodic factored mdps without knowledge of the transition function s in degree
International Conference on Machine Learning, 2011Co-Authors: Doran Chakraborty, Peter StoneAbstract:This paper introduces Learn Structure and Exploit Rmax (LSE-Rmax), a novel model based structure learning algorithm for ergodic factored-state MDPs. Given a planning horizon that satisfies a condition, LSE-Rmax provably guarantees a return very close to the optimal return, with a high certainty, without requiring any prior knowledge of the in-degree of the transition function as input. LSE-Rmax is fully implemented with a thorough analysis of its sample complexity. We also present empirical results demonstrating its effectiveness compared to prior approaches to the problem.
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ICML - Structure Learning in Ergodic Factored MDPs without Knowledge of the Transition Function's In-Degree
2011Co-Authors: Doran Chakraborty, Peter StoneAbstract:This paper introduces Learn Structure and Exploit Rmax (LSE-Rmax), a novel model based structure learning algorithm for ergodic factored-state MDPs. Given a planning horizon that satisfies a condition, LSE-Rmax provably guarantees a return very close to the optimal return, with a high certainty, without requiring any prior knowledge of the in-degree of the transition function as input. LSE-Rmax is fully implemented with a thorough analysis of its sample complexity. We also present empirical results demonstrating its effectiveness compared to prior approaches to the problem.
Sebastián A. Pardo - One of the best experts on this subject based on the ideXlab platform.
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Maximum intrinsic rate of population increase in sharks, rays, and chimaeras: the importance of survival to maturity
2016Co-Authors: Sebastián A. Pardo, Holly K. Kindsvater, John D. Reynolds, Nicholas K. DulvyAbstract:The maximum intrinsic rate of population increase Rmax is a commonly estimated demographic parameter used in assessments of extinction risk. In teleosts, Rmax can be calculated using an estimate of spawners per spawner, but for chondrichthyans, most studies have used annual reproductive output b instead. This is problematic as it effectively assumes all juveniles survive to maturity. Here, we propose an updated Rmax equation that uses a simple mortality estimator which also accounts for survival to maturity: the reciprocal of average lifespan. For 94 chondrichthyans, we now estimate that Rmax values are on average 10% lower than previously published. Our updated Rmax estimates are lower than previously published for species that mature later relative to maximum age and those with high annual fecundity. The most extreme discrepancies in Rmax values occur in species with low age at maturity and low annual reproductive output. Our results indicate that chondrichthyans that mature relatively later in life, and to a lesser extent those that are highly fecund, are less resilient to fishing than previously thought.
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Maximum intrinsic rate of population increase in sharks, rays, and chimaeras: the importance of survival to maturity
Canadian Journal of Fisheries and Aquatic Sciences, 2016Co-Authors: Sebastián A. Pardo, Holly K. Kindsvater, John D. Reynolds, Nicholas K. DulvyAbstract:The maximum intrinsic rate of population increase (Rmax) is a commonly estimated demographic parameter used in assessments of extinction risk. In teleosts, Rmax can be calculated using an estimate of spawners per spawner, but for chondrichthyans, most studies have used annual reproductive output (b) instead. This is problematic as it effectively assumes all juveniles survive to maturity. Here, we propose an updated Rmax equation that uses a simple mortality estimator that also accounts for survival to maturity: the reciprocal of average life-span. For 94 chondrichthyans, we now estimate that Rmax values are on average 10% lower than previously published. Our updated Rmax estimates are lower than previously published for species that mature later relative to maximum age and those with high annual fecundity. The most extreme discrepancies in Rmax values occur in species with low age at maturity and low annual reproductive output. Our results indicate that chondrichthyans that mature relatively later in life...
D.a. Grieve - One of the best experts on this subject based on the ideXlab platform.
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Biaxial vitrinite reflectance in coals of the Elk Valley coalfield, southeastern British Columbia, Canada
International Journal of Coal Geology, 1991Co-Authors: D.a. GrieveAbstract:Ninety-nine grab coal samples collected from ten different diamond drill-cores from the Jurassic-Cretaceous Mist Mountain Formation in the Elk Valley coalfield in southeastern British Columbia were analyzed petrographically for mean maximum vitrinite reflectance (Rmax), mean random vitrinite reflectance (Rm) and the lengths of the maximum, intermediate and minimum axes of the reflectance indicating surface or RIS of vitrinite (RmaxRint andRmin). Coal rank in the coalfield ranges from high-volatile A to low-volatile bituminous. Values of Rmax in the core samples range from 0.95 to 1.50%. Rmax, Rm, Rmax, Rint and Rmin are all strongly intercorrelated (r>0.89 in all combinations). The vitrinite in all samples is biaxial, in most cases biaxial negative. As a consequence, Rmax is always less than Rmax, the relationship being Rmax = 1.044 Rmax. There is no relationship between degree of vitrinite reflectance anisotropy, as represented by the RIS shape, and rank. The results indicate that a secondary stress field, not perpendicular to bedding, existed during coalification.
