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

Comparison of Selected Fuel and Chemical Content Values for Seven Populus Hybrid Clones

Fuel and chemical content values were determined for seven Populus clones by component (wood, bark, and wood/bark specimens) and tissue age (1 to 8 years old). The fuel and chemical content values obtained included: gross heat of combustion, extractives, holocellulose, alpha-cellulose, lignin, and ash. In general, analysis of the data for the wood, bark, and wood/bark specimens indicated that: 1) wood was higher in holocellulose and alpha-cellulose content than bark; 2) bark was higher in gross heat of combustion, lignin, extractive, and ash content values than wood; and 3) combined wood/bark fuel and chemical content values were usually between the individual values for the wood and bark.Statistical analyses indicated that significant differences existed within and among clones. Within the wood, bark, and wood/bark specimens, tissue age influenced the chemical content values more than the parentage. Potential chemical yields derived from the seven Populus hybrid clones investigated will depend on component and age with limited parentage effects