Stochastic Inverse Reinforcement Learning

The goal of the inverse reinforcement learning (IRL) problem is to recover the reward functions from expert demonstrations. However, the IRL problem like any ill-posed inverse problem suffers the congenital defect that the policy may be optimal for many reward functions, and expert demonstrations may be optimal for many policies. In this work, we generalize the IRL problem to a well-posed expectation optimization problem stochastic inverse reinforcement learning (SIRL) to recover the probability distribution over reward functions. We adopt the Monte Carlo expectation-maximization (MCEM) method to estimate the parameter of the probability distribution as the first solution to the SIRL problem. The solution is succinct, robust, and transferable for a learning task and can generate alternative solutions to the IRL problem. Through our formulation, it is possible to observe the intrinsic property for the IRL problem from a global viewpoint, and our approach achieves a considerable performance on the objectworld.Comment: 8+2 pages, 5 figures, Under Revie

Grazing to Gravy: Faunal Remains and Indications of Genízaro Foodways on the Spanish Colonial Frontier of New Mexico

Understanding identity aspects of those labeled Genízaro during the late Spanish Colonial period of New Mexico benefits from finer-grained perspectives on what ranges and mixtures of practices persons bearing this casta designation may have performed while preparing cuisine. Materials from the northern frontier site of Casitas Viejas (LA 917) suggest that the closely related households of this fortified plaza may have departed from the less expansive culinary practices of colonial elites while drawing from their multiple social relationships at the various stages of production and consumption of foods. In other words, at different temporal and spatial scales, behaviors reflected in the material record refute historical notions about a creolized community that tried to diminish identity difference within the village. The goal of this work is to explore through the study of faunal remains some of the relationships between foodways and cultural identity in a manner that might assist in some disentangling of the sticky problems archaeologists face in interpreting traces of dynamic past situations of identity from a static material record recovered today

Numerical analysis of parabolic p-Laplacian: Approximation of trajectories

The long time numerical approximation of the parabolic p-Laplacian problem with a time-independent forcing term and sufficiently smooth initial data is studied. Convergence and stability results which are uniform for t is an element of [0, infinity) are established in the L-2, W-1,W-p norms for the backward Euler and the Crank-Nicholson schemes with the finite element method (FEM). This result extends the existing uniform convergence results for exponentially contractive semigroups generated by some semilinear systems to nonexponentially contractive semigroups generated by some quasilinear systems

Signatures of strong correlation effects in RIXS on Cuprates

Recently, spin excitations in doped cuprates are measured using the resonant inelastic X-ray scattering (RIXS). The paramagnon dispersions show the large hardening effect in the electron-doped systems and seemingly doping-independence in the hole-doped systems, with the energy scales comparable to that of the antiferromagnetic magnons. This anomalous hardening effect was partially explained by using the strong coupling t-J model but with a three-site term(Nature communications 5, 3314 (2014)). However we show that hardening effect is a signature of strong coupling physics even without including this extra term. By considering the t-t'-t"-J model and using the Slave-Boson (SB) mean field theory, we obtain, via the spin-spin susceptibility, the spin excitations in qualitative agreement with the experiments. These anomalies is mainly due to the doping-dependent bandwidth. We further discuss the interplay between particle-hole-like and paramagnon-like excitations in the RIXS measurements.Comment: 7 pages, 6 figure