Impartial coloring games

Coloring games are combinatorial games where the players alternate painting uncolored vertices of a graph one of $k > 0$ colors. Each different ruleset specifies that game's coloring constraints. This paper investigates six impartial rulesets (five new), derived from previously-studied graph coloring schemes, including proper map coloring, oriented coloring, 2-distance coloring, weak coloring, and sequential coloring. For each, we study the outcome classes for special cases and general computational complexity. In some cases we pay special attention to the Grundy function

The Wearable Instrument Approach For Pilots

Pilot errors caused by heads-down time or misinterpretation of published instrument approach procedures have been attributed to multiple incidents of fatal controlled flight into terrain while approaching airports in instrument meteorological conditions. This study was motivated by the idea that wearable heads-up devices such as Google Glass can supplement standard paper or tablet-based instrument approach plates by decreasing heads-down time and pilot error. In order to evaluate the utility of Google Glass in the field of aviation, this thesis was comprised of two phases: the development of a custom instrument approach software application for Google Glass, and the execution of a simulator study to compare the effects between the usage of Google Glass and current tablet-based instrument approach plates in regards to pilot error, preference, and heads-down time. Results showed that the introduction of Google Glass into the cockpit can help pilots fly a safer approach when compared to simply using a tablet-based approach plate alone. More specifically, when Google Glass was used together with a tablet-based instrument approach plate, pilots had a quicker reaction time when they did indeed commit a navigational error, and their total heads-down time was reduced, allowing them to focus more on cockpit instrumentation and flying the aircraft. While Google Glass is currently a moot point in the gadget world, the knowledge gained from this research should translate well to the development of more advanced software for forthcoming wearable heads-up devices

Image Quality Indicator for Infrared Inspections

The quality of images generated during an infrared thermal inspection depends on many system variables, settings, and parameters to include the focal length setting of the IR camera lens. If any relevant parameter is incorrect or sub-optimal, the resulting IR images will usually exhibit inherent unsharpness and lack of resolution. Traditional reference standards and image quality indicators (IQIs) are made of representative hardware samples and contain representative flaws of concern. These standards are used to verify that representative flaws can be detected with the current IR system settings. However, these traditional standards do not enable the operator to quantify the quality limitations of the resulting images, i.e. determine the inherent maximum image sensitivity and image resolution. As a result, the operator does not have the ability to optimize the IR inspection system prior to data acquisition. The innovative IQI described here eliminates this limitation and enables the operator to objectively quantify and optimize the relevant variables of the IR inspection system, resulting in enhanced image quality with consistency and repeatability in the inspection application. The IR IQI consists of various copper foil features of known sizes that are printed on a dielectric non-conductive board. The significant difference in thermal conductivity between the two materials ensures that each appears with a distinct grayscale or brightness in the resulting IR image. Therefore, the IR image of the IQI exhibits high contrast between the copper features and the underlying dielectric board, which is required to detect the edges of the various copper features. The copper features consist of individual elements of various shapes and sizes, or of element-pairs of known shapes and sizes and with known spacing between the elements creating the pair. For example, filled copper circles with various diameters can be used as individual elements to quantify the image sensitivity limit. Copper line-pairs of various sizes where the line width is equivalent to the spacing between the lines can be used as element-pairs to quantify the image resolution limit

Early experiences of computer‐aided assessment and administration when teaching computer programming

This paper describes early experiences with the Ceilidh system currently being piloted at over 30 institutions of higher education. Ceilidh is a course‐management system for teaching computer programming whose core is an auto‐assessment facility. This facility automatically marks students programs from a range of perspectives, and may be used in an iterative manner, enabling students to work towards a target level of attainment. Ceilidh also includes extensive course‐administration and progress‐monitoring facilities, as well as support for other forms of assessment including short‐answer marking and the collation of essays for later hand‐marking. The paper discusses the motivation for developing Ceilidh, outlines its major facilities, then summarizes experiences of developing and actually using it at the coal‐face over three years of teaching

Compton Imaging Tomography for Nondestructive Evaluation of Spacecraft Thermal Protection Systems

Novel nondestructive evaluation (NDE) systems based on a recently pioneered Compton Imaging Tomography (CIT) technique [1-4] are currently being developed by Physical Optics Corporation (POC). CIT provides high-resolution, three-dimensional, Compton scattered X-ray imaging of the internal structure of evaluated objects, using a set of acquired two-dimensional, Compton scattered X-ray images of consecutive cross sections of these objects. Unlike conventional computerized tomography, CIT requires only one-sided access to objects, has no limitation on the dimensions and geometry of such objects, and can be applied to large, multilayer, nonuniform objects. Also, CIT does not require any contact with objects during its application. Currently POC is developing a CIT-based tool that addresses NASA’s need for NDE of lightweight, rigid, and/or flexible ablative materials (PICA, Avcoat, AETB, etc.), and provides noncontact, one-sided in situ operation for accurate detection, identification, and precise spatial localization and measurements of internal and surface defects (cracks, voids, delaminations, porosity, and inclusions), and evaluation of bondlines and in-depth integrity of such materials and also large-area multilayer thermal protection system (TPS) structures with complex geometries. The feasibility of the tool was successfully demonstrated in NDE of various TPS samples provided by NASA. This tool can detect individual internal defects with dimensions about 1 mm3, and bondline defects less than 6 mm by 6 mm by the thickness of the adhesive of ≤100 μm. Also, it can detect anisotropy of the TPS materials. It also allows precise detection of flaws and in-service damage for ceramic, metal matrix composite, textile polymeric, aluminum/ titanium materials/structures, providing quantitative information on residual structural performance. The current scanning speed of TPS structures is about 2.5 min/ft2 (25 min/m2): ~250 ft2 of an entire Orion TPS can be scanned in 10-12 hr

Making the Case for Exploratory World Language Instruction in Catholic Elementary Schools through University Partnerships

As a result of a university partnership, elementary students at two midwest Catholic elementary schools have been provided with exploratory world language instruction (FLEX) from pre-service teachers. To investigate students’ attitudes and learning of Spanish, researchers interviewed second and fourth graders. The students’ parents and pre-service teachers answered open-ended questionnaires. The research questions for this qualitative study were: 1) How does exploratory world language instruction (FLEX) affect children’s attitudes about learning world languages and cultures? 2) How does exploratory world language instruction (FLEX) affect children’s learning of a world language? The results showed that students possessed positive attitudes about world language instruction, and they learned numbers, colors, cultural information, and food and animal vocabulary, as well as how to communicate at the novice level. Universities should consider engaging in service-learning partnerships with Catholic elementary schools so students learn to open their minds and hearts to diverse languages and cultures. Como resultado de una colaboración con una universidad, se les ofreció a estudiantes de dos escuelas elementales católicas del medio oeste la enseñanza exploratoria de lenguas extranjeras (FLEX) por parte de docentes en prácticas. Para investigar las actitudes de los estudiantes y su aprendizaje de español, los investigadores entrevistaron a estudiantes de segundo y cuarto curso. Los padres de los estudiantes y los docentes en prácticas contestaron cuestionarios abiertos. Las preguntas de investigación para este estudio cualitativo fueron: (a) ¿Cómo afecta la enseñanza exploratoria de lenguas extranjeras (FLEX) a las actitudes de los niños frente al aprendizaje de lenguas y culturas del mundo? (b) ¿Cómo afecta la enseñanza exploratoria de lenguas extranjeras (FLEX) al aprendizaje por parte de los niños de una lengua del mundo? Los resultados mostraron que los estudiantes disponían de una actitud positiva sobre la enseñanza de lenguas del mundo, y aprendieron números, colores, información cultural, vocabulario de comida y animales, así como a comunicarse a un nivel básico. Las universidades deberían considerar participar en colaboraciones de aprendizaje-servicio con escuelas elementales católicas para que los estudiantes puedan abrir sus mentes y corazones a las diversas lenguas y culturas. Palabras clave: escuelas elementales, FLEX, aprendizaje-servicio, aprendizaje a través del servicio, lenguas del mund

A quantum-dot heat engine operating close to the thermodynamic efficiency limits

Cyclical heat engines are a paradigm of classical thermodynamics, but are impractical for miniaturization because they rely on moving parts. A more recent concept is particle-exchange (PE) heat engines, which uses energy filtering to control a thermally driven particle flow between two heat reservoirs. As they do not require moving parts and can be realized in solid-state materials, they are suitable for low-power applications and miniaturization. It was predicted that PE engines could reach the same thermodynamically ideal efficiency limits as those accessible to cyclical engines, but this prediction has not been verified experimentally. Here, we demonstrate a PE heat engine based on a quantum dot (QD) embedded into a semiconductor nanowire. We directly measure the engine's steady-state electric power output and combine it with the calculated electronic heat flow to determine the electronic efficiency $\eta$. We find that at the maximum power conditions, $\eta$ is in agreement with the Curzon-Ahlborn efficiency and that the overall maximum $\eta$ is in excess of 70$\%$ of the Carnot efficiency while maintaining a finite power output. Our results demonstrate that thermoelectric power conversion can, in principle, be achieved close to the thermodynamic limits, with direct relevance for future hot-carrier photovoltaics, on-chip coolers or energy harvesters for quantum technologies

Design of an Automated Ultrasonic Scanning System for In-Situ Composite Cure Monitoring and Defect Detection

The preliminary design and development of an automated ultrasonic scanning system for in-situ composite cure monitoring and defect detection in the high temperature environment of an oven was completed. This preliminary design is a stepping stone to deployment in the high temperature and high pressure environment of an autoclave, the primary cure method of aerospace grade thermoset composites. Cure monitoring with real-time defect detection during the process could determine when defects form and how they move. In addition, real-time defect detection during cure could assist validating physics-based process models for predicting defects at all stages of the cure cycle. A physics-based process model for predicting porosity and fiber waviness originating during cure is currently under development by the NASA Advanced Composites Project (ACP). For the design, an ultrasonic contact scanner is enclosed in an insulating box that is placed inside an oven during cure. Throughout the cure cycle, the box is nitrogen-cooled to approximately room temperature to maintain a standard operating environment for the scanner. The composite part is mounted on the outside of the box in a vacuum bag on the build/tool plate. The build plate is attached to the bottom surface of the box. The scanner inspects the composite panel through the build plate, tracking the movement of defects introduced during layup and searching for new defects that may form during cure. The focus of this paper is the evaluation and selection of the build plate material and thickness. The selection was based on the required operating temperature of the scanner, the cure temperature of the composite material, thermal conductivity models of the candidate build plates, and a series of ultrasonic attenuation tests. This analysis led to the determination that a 63.5 mm thick build plate of borosilicate glass would be utilized for the system. The borosilicate glass plate was selected as the build plate material due to the low ultrasonic attenuation it demonstrated, its ability to efficiently insulate the scanner while supporting an elevated temperature on the part side of the plate, and the availability of a 63.5 mm thick plate without the need for lamination

Egyptian Darkness: Antebellum Reconstruction and Southern Illinois in the Republican Imagination, 1854-1861

Historians have identified an antebellum Republican “critique of the South” outlining the detrimental effects of slavery on white Southern society and the vital importance of “reconstructing” the white South in the image of the free labor agrarian North following the eventual collapse of slavery. The efforts to follow through with this transformation have historiographically been relegated to the efforts of radical Republicans to reconstruct the ex-Confederacy between 1863 and 1877. This paper argues that Republican strategies and efforts to “reconstruct” the white South were evident during the late antebellum period (1848-1861) applied to the southern counties of Illinois, inhabited chiefly by Southern "poor white” migrants. These efforts to dispel the “Egyptian darkness” of southern Illinois can be seen as an early laboratory of Republican reconstruction strategies.Master of Art