1,186 research outputs found
The Subject Librarian Newsletter, Anthropology, Fall 2017
https://stars.library.ucf.edu/lib-news/1329/thumbnail.jp
A Simple Test Method for Large Deformation Bending of Thin High Strain Composite Flexures
A simple test method for large deformation bending of thin composite laminates is investigated using image processing and full-field strain measurements. The assumptions and kinematic equations that represent the test are used to calculate numerically the laminate bending stiffness and strength as well as the curvature and strains at failure. In order to validate the test methodology, a comparison is performed between analytical model predictions and empirical data in terms of computed surface strains versus digital image correlation data and calculated rotation angles of the fixture arms throughout the test versus measured ones. The new test method is then used to calculate the bending stiffness in the D11 and D22 directions as well as failure strains for various thin-ply laminates of interest. These parameters are ultimately compared with predicted values using micromechanics and classical lamination theory analysis. In general, bending stiffness and strain test results and predictions for 0 degree orientation coupons have a maximum difference of 10% and 35%
The Subject Librarian Newsletter, Sociology, Fall 2017
https://stars.library.ucf.edu/lib-news/1330/thumbnail.jp
History, Quantification, and the Social Sciences
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67009/2/10.1177_000276427702100202.pd
Hamilton-Jacobi Theory for Degenerate Lagrangian Systems with Holonomic and Nonholonomic Constraints
We extend Hamilton-Jacobi theory to Lagrange-Dirac (or implicit Lagrangian)
systems, a generalized formulation of Lagrangian mechanics that can incorporate
degenerate Lagrangians as well as holonomic and nonholonomic constraints. We
refer to the generalized Hamilton-Jacobi equation as the Dirac-Hamilton-Jacobi
equation. For non-degenerate Lagrangian systems with nonholonomic constraints,
the theory specializes to the recently developed nonholonomic Hamilton-Jacobi
theory. We are particularly interested in applications to a certain class of
degenerate nonholonomic Lagrangian systems with symmetries, which we refer to
as weakly degenerate Chaplygin systems, that arise as simplified models of
nonholonomic mechanical systems; these systems are shown to reduce to
non-degenerate almost Hamiltonian systems, i.e., generalized Hamiltonian
systems defined with non-closed two-forms. Accordingly, the
Dirac-Hamilton-Jacobi equation reduces to a variant of the nonholonomic
Hamilton-Jacobi equation associated with the reduced system. We illustrate
through a few examples how the Dirac-Hamilton-Jacobi equation can be used to
exactly integrate the equations of motion.Comment: 44 pages, 3 figure
Actor-Critic Policy Learning in Cooperative Planning
In this paper, we introduce a method for learning and adapting cooperative control strategies in real-time stochastic domains. Our framework is an instance of the intelligent cooperative control architecture (iCCA)[superscript 1]. The agent starts by following the "safe" plan calculated by the planning module and incrementally adapting its policy to maximize the cumulative rewards. Actor-critic and consensus-based bundle algorithm (CBBA) were employed as the building blocks of the iCCA framework. We demonstrate the performance of our approach by simulating limited fuel unmanned aerial vehicles aiming for stochastic targets. In one experiment where the optimal solution can be calculated, the integrated framework boosted the optimality of the solution by an average of %10, when compared to running each of the modules individually, while keeping the computational load within the requirements for real-time implementation.Boeing Scientific Research LaboratoriesUnited States. Air Force Office of Scientific Research (Grant FA9550-08-1-0086
- …