Distributed utterances

I propose an apparatus for handling intrasentential change in context. The standard approach has problems with sentences with multiple occurrences of the same demonstrative or indexical. My proposal involves the idea that contexts can be complex. Complex contexts are built out of (“simple”) Kaplanian contexts by ordered n-tupling. With these we can revise the clauses of Kaplan’s Logic of Demonstratives so that each part of a sentence is taken in a different component of a complex context. I consider other applications of the framework: to agentially distributed utterances (ones made partly by one speaker and partly by another); to an account of scare-quoting; and to an account of a binding-like phenomenon that avoids what Kit Fine calls “the antinomy of the variable.

Flight test trajectory control analysis

Recent extensions to optimal control theory applied to meaningful linear models with sufficiently flexible software tools provide powerful techniques for designing flight test trajectory controllers (FTTCs). This report describes the principal steps for systematic development of flight trajectory controllers, which can be summarized as planning, modeling, designing, and validating a trajectory controller. The techniques have been kept as general as possible and should apply to a wide range of problems where quantities must be computed and displayed to a pilot to improve pilot effectiveness and to reduce workload and fatigue. To illustrate the approach, a detailed trajectory guidance law is developed and demonstrated for the F-15 aircraft flying the zoom-and-pushover maneuver

Investigation of Dynamic Store Separation out of a Weapons Bay Cavity Utilizing a Low Speed Wind Tunnel

Characterizing mission store trajectories as they separate from a weapons bay cavity is highly relevant to the Air Force mission. The flow around a weapons bay is unsteady. The unsteady flow can cause a mission store separation trajectory to be unpredictable, and such is the case for what some have termed a pitch bifurcation. Traditional wind tunnel testing is incapable of detecting a bifurcation because traditional wind tunnel testing records time-averaged data. In this study, an experimental testing system was developed and refined in order to support the time-accurate characterization of dynamic mission store separation events. A Motion Test Apparatus integrated with a low-speed wind tunnel maneuvers a model within the wind tunnel test section along a prescribed trajectory. A dedicated data acquisition system, along with sensors, record time-accurate force-and-moment measurements as well as model attitude. Two mission store geometries fabricated of two different materials were studied as they performed a one-off store separation trajectory from a weapons bay cavity. The mission store models separated, alternatively, from forward and aft positions from the weapons bay. Data confirmed that variability in pitch moment experienced by the models was higher for store separation from the aft position. Force-and-moment data also suggests a bifurcation was present for certain test cases

Time-dependent Validation of Finite Element Strain Distribution of a Plastically-Deformed Plate via Digital Image Correlation

Generation of residual stress is an essential step in the generation of Goodman data via Air Force Research Laboratory\u27s vibration-based fatigue test. Conventional Goodman data is constructed through uniaxial fatigue testing at a rate of 40 Hz, while the vibration-based testing excites stresses at 1,600 Hz in a stress state that is similar to those seen in gas turbine engine airfoils. A pre-strain procedure is conducted to form residual tensile stress, which serves as a steady stress when the specimen is subjected to fully-reversed vibration-based fatigue loads. This steady tensile stress is desired at the fatigue zone of the test article, but is the result of an adjacent compressive region in equilibrium, and as such, a FEM is necessary to determine the stress distribution throughout the entire sample. The goal of this work is to improve the FEM analysis associated with the pre-strain method for better accuracy of steady stress generation for Goodman data fatigue assessment. Improvements were made to the FEM by more effectively incorporating empirical tensile stress-strain behavior, in addition to more accurately representing the pressures and forces acting on the specimen during monotonic loading. Validations of improvements to the pre-strain steady stress generation procedure will be demonstrated on Aluminum 6061-T6 by comparing strain field results from digital image correlation to FEM analysis. The converged quasi-static FEM solution had a standard deviation in epsilon yy of 2,557 microstrain and predicted a residual sigma yy of 10.72 ksi, while the optimized time-dependent solution had a standard deviation in epsilon yy of 308.9 microstrain (less than the experimental variation of 376.1 microstrain) and predicted a residual sigma yy of 4.93 ksi. The increased accuracy of these models altered residual stresses on a Goodman line by as much as 26 compared with past results

IPL: Interfaced Prolog/Lisp

This thesis report describes the design and implementation of an interface between the two most common artificial intelligence languages, Lisp and Prolog. The interface is accomplished by small extensions to each language, and provides Prolog programs with the capability of invoking Lisp functions. The interface is simple yet powerful; it the supports passing of arbitrarily complex data objects, regardless of data type. The particular language implementations extended were C-Prolog [Pereira,85] and XLISP [Betz,86], both interpreters running under the Unix operating system

Language Barriers in Health Care Settings: An Annotated Bibliography of Research Literature

Provides an overview of resources related to the prevalence, role, and effects of language barriers and access in health care