Career education\u27s weak link: teacher education

Career education is no fly-by-night passing fad. Teachers are recognizing this and making a serious commitment to the movement

Advanced techniques for safety-of-life carrier phase differential GNSS positioning with applications to triplex architectures

Safety-of-life Carrier phase Differential Global Navigation Satellite System (CDGNSS) positioning systems must provide guarantees that their position estimates have errors that are smaller than specified levels, called alert limits (AL). These guarantees are specified as an allowable probability, called integrity risk (IR), that the error exceeds its AL. Typical values of IR are between 10⁻⁹ and 10⁻⁷, per hour of operation. CDGNSS positioning has been demonstrated to provide centimeter-accurate estimates of a vehicle's location when the so-called integer ambiguities are resolved; however, in safety-of-life applications, the probability of incorrectly resolving the integer ambiguities frequently exceeds the allowable IR. To address this limitation, existing algorithms bound the positioning error caused by incorrectly resolved ambiguities. If such bounds satisfy the AL, then the integer-resolved, or fixed, solution can be used. Unfortunately, the positioning error from incorrect fixing can exceed several meters, which fails to satisfy the most demanding ALs for autonomous vehicles. This dissertation offers three contributions to the science of CDGNSS positioning for safety-of-life applications. First, a novel algorithm is developed that validates the correctness of integer ambiguity estimates. This algorithm, called Generalized Integer Aperture Bootstrapping (GIAB), establishes a rigorous, fixed-missed-detection-rate test that provides a guarantee that the integer ambiguities have been fixed correctly. GIAB also allows for partial fixing, where a subset of the ambiguities are resolved. Partial fixing allows for graceful degradation of positioning when measurement quality is poor. GIAB is derived analytically and validated via Monte Carlo simulation. Its performance is compared with existing ambiguity validation techniques. Second, the probability density function of the positioning estimate resulting from GIAB is derived. This distribution leads to a provable bound on the IR that the estimate has errors exceeding the specified ALs. This bound allows GIAB to be used for safety-of-life application while satisfying ALs of less than a meter. Third, triplex CDGNSS architectures, in which the vehicle position is estimated using three separate navigation systems with mid-level voting (MLV) logic, are analyzed. Such architectures are commonly used since they are robust to single equipment failures, but the integrity benefit of their fault-free performance has not previously been evaluated. It is shown that integer-fixed CDGNSS solutions improve in accuracy performance, but gain no integrity benefit. However, when the integer constraint is not enforced, the so called CDGNSS float solution benefits greatly from MLV in both accuracy and integrity performance.Electrical and Computer Engineerin

SCHOOL CONSOLIDATION AND COMMUNITY DEVELOPMENT

The linkages between schools and community are seldom discussed in the research on school consolidation. Most of the focus of this body of literature is on the effects of school consolidation on efficiency and equity. In this essay I discuss the importance of school-community relationships and the critical role schools can play in community development. School consolidation can have several negative impacts on the local economy, social capital, and community identity. Assessments of the benefits and costs of consolidation need to consider more carefully the impacts on communities and the potential of building a stronger relationship between schools and communities

Length-length and weight-length relationships of seven deep-water fishes in the Gulf of Mexico

Regression coefficients for equations of the form Y = a + bX were estimated for total length (TL) and whole weight (W) as a function of standard length (SL) and fork length (FL) and vice versa for seven deep-water fishes. All lengths were measured in millimeters and all weights in grams. There was a significant correlation between weight and length and the types of length measurements for all species. However, the amount of variation explained by each regression varied among species. Weight-length regressions were less precise than length-length regression, as they generally are, because weights of small fish measured at sea are more inaccurate than those of large fish.Marine Scienc

The Political Economy of Organisational Violence in Chinese Industry

"Organisational violence" involves wilful, illegal business behaviour that has the potential to harm workers, consumers, or the environment. We use a combined perspective from the fields of political economy and criminology to examine the incongruously high level of organisational violence among Chinese firms that exists despite robust efforts by the government to put forth regulatory laws that prohibit it. As the explanation for this incongruity, we assert two conditions that synergistically interact in a bidirectional relationship: 1) the complex legal structural barriers to effective enforcement against organisational violence caused by a politically biased and administratively fragmented Chinese political system, and 2) a socially disorganised business environment that does not recursively message the wrongfulness of organisational violence. The analysis rejects not only financial gain as a relevant factor in the commission of organisational violence but also other current perspectives on the causes of organisational violence in China

Comparisons of elastic and rigid blade-element rotor models using parallel processing technology for piloted simulations

A piloted comparison of rigid and aeroelastic blade-element rotor models was conducted at the Crew Station Research and Development Facility (CSRDF) at Ames Research Center. A simulation development and analysis tool, FLIGHTLAB, was used to implement these models in real time using parallel processing technology. Pilot comments and quantitative analysis performed both on-line and off-line confirmed that elastic degrees of freedom significantly affect perceived handling qualities. Trim comparisons show improved correlation with flight test data when elastic modes are modeled. The results demonstrate the efficiency with which the mathematical modeling sophistication of existing simulation facilities can be upgraded using parallel processing, and the importance of these upgrades to simulation fidelity