Development of the Distributed Points Method with Application to Cavitating Flow

A mesh-less method for solving incompressible, multi-phase flow problems has been developed and is discussed along with the presentation of benchmark results showing good agreement with theoretical and experimental results. Results of a systematic, parametric study of the single phase flow around a 2D circular cylinder at Reynolds numbers up to 1000 are presented and discussed. Simulation results show good agreement with experimental results. Extension of the method to deal with multiphase flow including liquid-to-vapor phase transition along with applications to cavitating flow are discussed. Insight gleaned from numerical experiments of the cavity closure problem are discussed along with recommendations for additional research. Several conclusions regarding the use of the method are made

Development of the Distributed Points Method with Application to Cavitating Flow

A mesh-less method for solving incompressible, multi-phase flow problems has been developed and is discussed along with the presentation of benchmark results showing good agreement with theoretical and experimental results. Results of a systematic, parametric study of the single phase flow around a 2D circular cylinder at Reynolds numbers up to 1000 are presented and discussed. Simulation results show good agreement with experimental results. Extension of the method to deal with multiphase flow including liquid-to-vapor phase transition along with applications to cavitating flow are discussed. Insight gleaned from numerical experiments of the cavity closure problem are discussed along with recommendations for additional research. Several conclusions regarding the use of the method are made

A Multi-Vehicle Cooperative Localization Approach for an Autonomy Framework

Offensive techniques produced by technological advancement present opportunities for adversaries to threaten the operational advantages of our joint and allied forces. Combating these new methodologies requires continuous and rapid development towards our own set of \game-changing technologies. Through focused development of unmanned systems and autonomy, the Air Force can strive to maintain its technological superiority. Furthermore, creating a robust framework capable of testing and evaluating the principles that define autonomy allows for the exploration of future capabilities. This research presents development towards a hybrid reactive/deliberative architecture that will allow for the testing of the principles of task, cognitive, and peer flexibility. Specifically, this work explores peer flexibility in multi-robot systems to solve a localization problem using the Hybrid Architecture for Multiple Robots (HAMR) as a basis for the framework. To achieve this task a combination of vehicle perception and navigation tools formulate inferences on an operating environment. These inferences are then used for the construction of Factor Graphs upon which the core algorithm for localization implements iSAM2, a high performing incremental matrix factorization method. A key component for individual vehicle control within the framework is the Unified Behavior Framework (UBF), a behavior-based control architecture which uses modular arbitration techniques to generate actions that enable actuator control. Additionally, compartmentalization of a World Model is explored through the use of containers to minimize communication overhead and streamline state information. The design for this platform takes on a polymorphic approach for modularity and robustness enabling future development

Research relative to the development of a cryogenic microwave cavity gradiometer for orbital use

The noncryogenic, single axis, gravity gradiometer which is characterized by a sensitivity of the order of 10 to the minus 2 power Eovos Units in a few sec integration time was investigated. The prototype of testing gradiometer on the earth surface by the free fall in vacuo method was expanded. An existing free fall tower facility and the possibility of adding inside the falling elevator cabin an air tight, sealed, cylindrical container with inside pressure or = -0.001 Torr were examined to test the gradiometer in free fall conditions inside this evacuated container. Earth's gravity anomalies are simulated with masses of suitable shape, weight, and location. The attitude of the falling gradiometer is monitored by a three axis gyro package mounted on the instrument package. It is concluded that the free fall testing of the gradiometer is both feasible and practical

Building Capacity for Academically Productive Talk: The Development of Teacher Leaders in Science Professional Development

Despite decades of research on the type of classroom dialogue that supports collaborative student sensemaking and professional development efforts to support such dialogue, opportunities for students to incrementally deepen their understanding of science ideas through engagement in science practices and to engage in complex reasoning and argumentation through classroom talk is limited in most K-12 science classrooms (Driver, Newton, & Osborne, 2000; Lemke, 1990; Michaels, Shouse, & Schweingruber, 2008; Mortimer & Scott, 2003; C. O’Connor, Michaels, & Chapin, 2015; Reinsvold & Cochran, 2011; Scott, Mortimer, & Aguiar, 2006; Weiss, Pasley, Smith., Banilower, and Heck, 2003; Wilson, Schweingruber, & Nielsen, 2015). In order to address the bigger question of how to prepare PD Leaders to support the knowledge and enactment of new discourse practices, I used the framework of Academically Productive Talk (APT) and examined the discourse practices used by Lead Facilitators as they prepare Teacher Leaders to enact PD focused on APT. I then examined the discourse practices used by those Teacher Leaders as they enacted the PD with their teacher colleagues. Analysis revealed that, similar to the Lead Facilitators, Teacher Leaders at both Bayedge and Lakecastle used APT moves at a high rate and used the conceptual and pedagogical goals of the discussion to guide their use of those moves in discussions that were characterized by high levels of participant to participant interaction and co-construction. Moves where the Teacher Leaders were guiding the discussion by synthesizing ideas and naming the ideas they want the group to attend to were unequally taken up indicating further work is needed in supporting Teacher Leaders with moves that can support idea development while at the same time ensuring that the Teachers are doing the sensemaking. Greater attention around specific moves designed to support idea development by synthesizing the discussion along the way may support Teacher Leaders in more readily taking up those moves. Engaging in the PD themselves as learners and providing opportunities to reflect on those experiences in order to deepen content understanding, understand the goals of each activity, and to develop a culture that supports adult learners appears to be important in this preparation of Teacher Leaders to lead PD on APT

An Evaluation on the Performance of Code Generated with WebAssembly Compilers

WebAssembly is a new technology that is revolutionizing the web. Essentially it is a low-level binary instruction set that can be run on browsers, servers or stand-alone environments. Many programming languages either currently have, or are working on, compilers that will compile the language into WebAssembly. This means that applications written in languages like C++ or Rust can now be run on the web, directly in a browser or other environment. However, as we will highlight in this research, the quality of code generated by the different WebAssembly compilers varies and causes performance issues. This research paper aims to evaluate the code generated by a number of existing WebAssembly compilers in order to determine whether or not there is a significant difference in their performances regarding execution times