Data-Driven Generalized Integer Aperture Bootstrapping for Real-Time High Integrity Applications

A new method is developed for integer ambiguity resolution in carrier-phase differential GPS (CDGPS) positioning. The method is novel in that it is (1) data-driven, (2) generalized to include partial ambiguity resolution, and (3) amenable to a full characterization of the prior and posterior distributions of the three-dimensional baseline vector that results from CDGPS. The technique is termed generalized integer aperture bootstrapping (GIAB). GIAB improves the availability of integer ambiguity resolution for high-integrity, safety-critical systems. Current high-integrity CDGPS algorithms, such as EPIC and GERAFS, evaluate the prior risk of position domain biases due to incorrect integer ambiguity resolution without further validation of the chosen solution. This model-driven approach introduces conservatism which tends to reduce solution availability. Common data-driven ambiguity validation methods, such as the ratio test, control the risk of incorrect ambiguity resolution by shrinking an integer aperture (IA), or acceptance region. The incorrect fixing risk of current IA methods is determined by functional approximations that are inappropriate for use in safety-of-life applications. Moreover, generalized IA (GIA) methods incorrectly assume that the baseline resulting from partial ambiguity resolution is zero mean. Each of these limitations is addressed by GIAB, and the claimed improvements are validated by Monte Carlo simulation. The performance of GIAB is then optimized by tuning the integer aperture size to maximize the prior probability of full ambiguity resolution. GIAB is shown to provide higher availability than EPIC for the same integrity requirements.Aerospace Engineering and Engineering Mechanic

Parents\u27 Perceptions of Activity Restrictions in Children with Epilepsy: First Two Years Post-Diagnosis

Children with epilepsy are less physically and socially active than their peers. The objective is to explore whether parents represent a barrier to children’s activity, by examining associations between child and family factors and parents’ perceptions of epilepsy-related activity restrictions. Data were from the Health Related Quality of Life in Children with Epilepsy Study, a longitudinal study of children 4-12 years old with new-onset epilepsy. Parents reported on activity restrictions and family factors and neurologists reported on epilepsy-related characteristics at baseline, 6, 12, and 24 months. Linear mixed models were used to model relationships among child and family factors and parents’ perceptions of activity restrictions. Parents’ response rate was 82%. There was significant non-linear improvement in activity restriction over time. Significant child factors suggest that perceptions are largely influenced by seizure-related risks. Significant family factors suggest an opportunity through parental education to reduce unnecessary activity restrictions in children with epilepsy

Development of a high altitude balloon payload data collection, telemetry, and recovery system

High altitude balloons are an effective, inexpensive and readily available conduit for conducting near space and low Reynolds number experimentation. Experiments are being developed that will use high altitude balloons as carriers for near space and low Reynolds test vehicles. The first step in developing this capability is to create a system that is able to log collected data and track and control a high altitude balloon payload. It is also beneficial that this system be flexible enough to accept different sensor types, communication methods and connection and release linkages. By combining the flexibility of microcontroller biased circuitry and the availability of commercial off the shelf products an economical design solution to this problem has been be achieved. Analysis of this system has been performed and the design has been fabricated, tested and specially modified to withstand the extreme conditions of high altitude flight

Chemical and physical modification of petroleum, coal-tar, and coal-extract pitches by air-blowing

Treatment by air-blowing was pursued as a process to modify the properties of pitches. The focus of this research was to compare the effects of air-blowing a coal-extract pitch with a petroleum pitch and coal-tar binder pitch. Hydrogenation of a bituminous coal in tetralin was used to produce the coal-extract pitch. The three pitches were air-blown in a 1-liter autoclave at temperatures of 250°C, 275°C, and 300°C for various time periods. The air-blown pitches were then characterized by softening point, coke yield, solubility, viscosity, density, elemental analysis, thermogravimetric analysis, FTIR, and optical texture. The results showed that air-blowing was a very effective way to increase the softening point, coke yield, density, and viscosity for all of the materials. The viscosity of the pitches was described well using the WLF model. Air blowing increased the carbon-to-hydrogen ratio, but little oxygen was incorporated into the pitch product. van Krevelen diagrams indicated that the coal-extract, petroleum, and coal-tar pitch each followed different mechanisms during the course of air blowing, emphasizing that compositional details must be considered in describing reaction details. Kinetic modeling of the air-blowing process showed an activation energy of approximately 16 kcal/mol for all three pitches. The optical texture of all of the pitches was purely isotropic before and after air-blowing treatment. The pitches were carbonized and their respective green cokes displayed a highly anisotropic structure

Walkable school neighborhoods are not playable neighborhoods

AbstractThe objectives were to determine whether: (1) playability features differed across walkable and non-walkable school neighborhoods, and (2) physical activity differed in children living in walkable and non-walkable school neighborhoods. A total of 3912 grade 6–8 students from 132 school neighborhoods were studied. There was more developed park space in high walkability neighborhoods than low walkability neighborhoods. Other playability features were more preferable in the low (e.g., undeveloped treed and water areas) and moderate (e.g., physical disorder/esthetics) walkability neighborhoods. Children from low walkability neighborhoods were more likely to engage in free-time physical activity outside of school and to achieve recommended levels of moderate-to-vigorous physical activity than were children from high walkability neighborhoods

Walkable school neighborhoods are not playable neighborhoods

AbstractThe objectives were to determine whether: (1) playability features differed across walkable and non-walkable school neighborhoods, and (2) physical activity differed in children living in walkable and non-walkable school neighborhoods. A total of 3912 grade 6–8 students from 132 school neighborhoods were studied. There was more developed park space in high walkability neighborhoods than low walkability neighborhoods. Other playability features were more preferable in the low (e.g., undeveloped treed and water areas) and moderate (e.g., physical disorder/esthetics) walkability neighborhoods. Children from low walkability neighborhoods were more likely to engage in free-time physical activity outside of school and to achieve recommended levels of moderate-to-vigorous physical activity than were children from high walkability neighborhoods

Intellectual Creativity, the Arts, and the University

As virtues of intellectual character are commonly discussed, they aim at propositional intellectual goods. But some creative works—especially those in music and the visual arts—are not primarily intended to gain, keep, or share propositional goods such as truth, knowledge, and understanding. They aim at something else. Thus, to conceive of intellectual creativity in a way that accords with standard discussions of intellectual virtue is to exclude paradigmatic works of the creative intellect. There is a kind of puzzle here: it appears that we cannot maintain both the commonly-discussed notion of intellectual virtue and the claim that, say, Beethoven’s Ninth, or Monet’s Water Lilies, are central cases of intellectually virtuous creativity. We provide a two-part solution to the puzzle. First, we suggest that some works of music and visual art can convey propositional goods. Second, we appeal to the notion of acquaintance as an epistemic good that is conveyed through creative artistic and musical to an extent not conveyed in standard prose works. In this respect, intellectual creativity is the virtue that breaks the propositional mold of much contemporary virtue epistemology

Toward Intellectually Virtuous Discourse: Two Vicious Fallacies and the Virtues that Inhibit Them

We have witnessed the athleticization of political discourse, whereby debate is treated like an athletic contest in which the aim is to vanquish one's opponents. When political discourse becomes a zero-sum game, it is characterized by suspicions, accusations, belief polarization, and ideological entrenchment. Unfortunately, athleticization is ailing the classroom as well, making it difficult for educators to prepare students to make valuable contributions to healthy civic discourse. Such preparation requires an educational environment that fosters the intellectual virtues that characterize an examined life. This, in turn, requires an amicable and hospitable atmosphere in which a student enjoys the freedom to discover and articulate what she believes, how well her beliefs hang together, and what underlying assumptions or biases might be at work—without the fear that her self-disclosure will trigger immediate accusations and pigeonholing from fellow students. Educating for intellectual virtue is crucial for meeting these challenges and in this chapter we contribute to this strategy by offering some tools and guidance for promoting productive discussion of controversial issues. In the first two sections, we identify and explain two fallacious patterns of thought that often encumber discussion of controversial issues: assailment-by-entailment and the attitude-to-agent fallacy. In effect, these sections diagnose two diseases of discourse. We conclude each section with practical suggestions—in the form of thinking routines—for curing these ills. We will argue that part of the cure is to be found in the intellectual virtues. In particular, we will discuss how the virtues of intellectual charity, humility and carefulness can inoculate the mind against the fallacies we identify