CERN Document Server

Shaping has proven to be a powerful but precarious means of improving reinforcement learning performance. Ng, Harada, and Russell (1999) proposed the potential-based shaping algorithm for adding shaping rewards in a way that guarantees the learner will learn optimal behavior. In this note, we prove certain similarities between this shaping algorithm and the initialization step required for several reinforcement learning algorithms. More specifically, we prove that a reinforcement learner with initial Q-values based on the shaping algorithm's potential function make the same updates throughout learning as a learner receiving potential-based shaping rewards. We further prove that under a broad category of policies, the behavior of these two learners are indistinguishable. The comparison provides intuition on the theoretical properties of the shaping algorithm as well as a suggestion for a simpler method for capturing the algorithm's benefit. In addition, the ...

Energy Technology Data Exchange (ETDEWEB)

We describe a liquid hydrogen droplet as an optical cavity via whispering gallery modes. We show that the droplet leads to an ultrahigh-cavity-Q value of 2.5x10{sup 9} in visible region. We show also that the high-Q droplet results in a huge Raman nonlinearity, generating a stimulated Raman comb series covering whole visible region.

International Nuclear Information System (INIS)

The mass asymmetry of fragments from nuclear fission of heavy nuclei is reviewed. While mass asymmetry is a common and well-known phenomenon for low-energy fission of the lighter actinides, more recent experiments have demonstrated that, for the heaviest actinides, the mass distribution switches to a symmetric one. On the other hand, it has been discovered that, though for fissioning nuclei with mass numbers A< or #approx#225 the mass distribution is basically symmetric, an asymmetric component is clearly to be identified for nuclei down to the Pb-region. In the absence of a generally accepted dynamical theory of fission, the above experimental findings are discussed in terms of static energy considerations. Triggered from the outset by the structure of the potential energy surface at the saddlepoint, the energy balance at the scission point between the available energy (Q-value) of the reaction and the Coulomb and deformation energy of the nascent fragments is ...

Energy Technology Data Exchange (ETDEWEB)

The receptor occupancy-biological effect relationship for muscarinic receptors in guinea pig ileal smooth muscle has been studied by comparison of radioligand binding and contractile response. Muscarinic receptors in homogenates of ileal smooth muscle were labeled with (/sub 3/H)-1-Quinuclidinyl benzilate. Treatment with propylbenzilylcholine mustard (PrBCM), to inactivate irreversibly muscarinic receptors, caused a large dose dependent rightward shift of the dose-response curve to three agonistic furtrethonium derivatives with a concomitant decrease in maximal response. Using those data, the fraction of receptors remaining unoccupied (q-values) and true affinity constants (-log K/sub A/-values) were calculated. Exposure to 20 or 60 nM PrBCM for 15 minutes resulted in a 39% and a 61% reduction in specific (/sup 3/H)-1-Quinuclidinyl benzilate binding sites respectively to be compared with a 62% and a 85% decrease expected from calculated ...

International Nuclear Information System (INIS)

A formalism for the dynamical treatment of the molecular orbitals of valence nucleons in nucleus-nucleus collisions is developed with the use of the coupled-reaction-channel (CRC) method. The Coriolis coupling effects as well as the finite mass effects of the nucleon are taken into account in this model, of rotating molecular orbitals, RMO. First, the validity of the concept is examined from the viewpoint of the multi-step processes in a standard CRC calculation for systems containing two identical [core] nuclei. The calculations show strong CRC effects particularly in the case where the mixing of different l-parity orbitals - called hybridization in atomic physics - occurs. Then, the RMO representation for active nucleons is applied to the same systems and compared to the CRC results. Its validity is investigated with respect to the radial motion (adiabaticity) and the rotation of the molecular axis (radial and rotational coupling). Characteristic molecular orbitals of covalent ...