Likelihood ratio policy gradient methods have been some of the most successful reinforcement learning algorithms, especially for learning on physical systems. We describe how the likelihood ratio policy gradient can be derived from an importance sampling perspective. This derivation highlights how likelihood ratio methods under-use past experience by (i) using the past experience to estimate on...

A statistical study of global galaxy parameters can help to improve our understanding of galaxy formation processes. In this paper we present the analysis of global galaxy parameters based on optical and near-infrared observations of a large sample of edgeon disc galaxies. We found a correlation between the ratio of the radial to vertical scale parameter and galaxy type: galaxies become systema...

Purpose: To compare the measurement of AC/A ratios while using the gradient method with plus or minus lenses at a fixed near point Method: A convenience sampling method of 30 Malaysians aged 13 to 30 years was used in this study. Relevant demographic and clinical data were obtained. The measurement of the near phoria was performed with a Maddox wing using both plus and minus lenses. The AC/A ra...

A newly developed polynomial preserving gradient recovery technique is further studied. The results are twofold. First, error bounds for the recovered gradient are established on the Delaunay type mesh when the major part of the triangulation is made of near parallelogram triangle pairs with -perturbation. It is found that the recovered gradient improves the leading term of the error by a facto...

study area is located in the central kopehdagh north of bojnurd and shirvan cities, between kakli and raz villages. aim of this research is separating high activity area from low activity. in this study, in order to evaluate rate of tectonic activity, stream length-gradient index (sl), ratio of valley floor width to valley height (vf), transverse topographic system (t), hypsometric integral (hi...

In this paper the nano conical shell model is developed based on modified strain gradient theory. The governing equations of the nano truncated conical shell are derived using the FSDT, and the size parameters through modified strain gradient theory have been taken into account. Hamilton’s principle is used to obtain the governing equations, and the shell’s equations of motion are derived with ...

INTRODUCTION AND OBJECTIVES The prognosis of patients with severe aortic stenosis, low aortic gradient and preserved ejection fraction is controversial. Our study analyzed the prognosis of these patients and its relation to pressure gradient and aortic valve flow. METHODS We performed a retrospective cohort study of 363 consecutive patients with severe aortic stenosis and preserved ejection f...

in this paper, direct numerical simulation of two-phase incompressible gas-liquid flow for simulation of bubble motion in a microtube is presented. microtube radius is 10 µm. the interface is tracked using volume of fluid (vof) method with continuous surface force (csf) model. the flow is solved using a finite volume scheme, based on piso algorithm. numerical simulation is performed on a axisym...

present paper is devoted to stress and deformation analyses of heated variable thickness functionally graded (fg) circular plate with clamped supported, embedded on a gradient elastic foundation and subjected to non-uniform transverse load. the plate is coupled by an elastic medium which is simulated as a winkler- pasternak foundation with gradient coefficients in the radial and circumferential...