Full-envelope aerodynamic modeling of the Harrier aircraft

A project to identify a full-envelope model of the YAV-8B Harrier using flight-test and parameter identification techniques is described. As part of the research in advanced control and display concepts for V/STOL aircraft, a full-envelope aerodynamic model of the Harrier is identified, using mathematical model structures and parameter identification methods. A global-polynomial model structure is also used as a basis for the identification of the YAV-8B aerodynamic model. State estimation methods are used to ensure flight data consistency prior to parameter identification.Equation-error methods are used to identify model parameters. A fixed-base simulator is used extensively to develop flight test procedures and to validate parameter identification software. Using simple flight maneuvers, a simulated data set was created covering the YAV-8B flight envelope from about 0.3 to 0.7 Mach and about -5 to 15 deg angle of attack. A singular value decomposition implementation of the equation-error approach produced good parameter estimates based on this simulated data set

Multiloop Manual Control of Dynamic Systems

Human interaction with a simple, multiloop dynamic system in which the human's activity was systematically varied by changing the levels of automation was studied. The control loop structure resulting from the task definition parallels that for any multiloop manual control system, is considered a sterotype. Simple models of the human in the task, and upon extending a technique for describing the manner in which the human subjectively quantifies his opinion of task difficulty were developed. A man in the loop simulation which provides data to support and direct the analytical effort is presented

A novel chromosome segregation mechanism during female meiosis.

In a wide range of eukaryotes, chromosome segregation occurs through anaphase A, in which chromosomes move toward stationary spindle poles, anaphase B, in which chromosomes move at the same velocity as outwardly moving spindle poles, or both. In contrast, Caenorhabditis elegans female meiotic spindles initially shorten in the pole-to-pole axis such that spindle poles contact the outer kinetochore before the start of anaphase chromosome separation. Once the spindle pole-to-kinetochore contact has been made, the homologues of a 4-μm-long bivalent begin to separate. The spindle shortens an additional 0.5 μm until the chromosomes are embedded in the spindle poles. Chromosomes then separate at the same velocity as the spindle poles in an anaphase B-like movement. We conclude that the majority of meiotic chromosome movement is caused by shortening of the spindle to bring poles in contact with the chromosomes, followed by separation of chromosome-bound poles by outward sliding

Finding an identity and meeting a standard : connecting the conflicting in teacher induction

This article has the apparently contradictory aims of describing a discourse of new teachers that is at odds with the policy-derived competence-based discourse of the professional standard for teachers, but of also seeking to find some points of connection that may help start a dialogue between policy and research. The experience of new teachers is conceptualized as personal stories of identity formation with a clear emotional-relational dimension and a sense of self and intrinsic purpose in which others, especially colleagues and children, are central - themes not visible in the standard. The empirical context is that of new teachers in Scotland but the argument is supported through a wider literature that extends beyond the traditional limits of teacher education, drawing on, for example, notions of self-identity, pure relationship and ontological security in the work of Giddens. Whether a more constructive dialogue can begin depends partly on the extent to which the formal standard can be expected to capture the complex, personal nature of the beginner's experience, and partly on the possibility of research identifying particular areas of competence, such as understanding difference, that connect in some way to the standard

A flight-test methodology for identification of an aerodynamic model for a V/STOL aircraft

Described is a flight test methodology for developing a data base to be used to identify an aerodynamic model of a vertical and short takeoff and landing (V/STOL) fighter aircraft. The aircraft serves as a test bed at Ames for ongoing research in advanced V/STOL control and display concepts. The flight envelope to be modeled includes hover, transition to conventional flight, and back to hover, STOL operation, and normaL cruise. Although the aerodynamic model is highly nonlinear, it has been formulated to be linear in the parameters to be identified. Motivation for the flight test methodology advocated in this paper is based on the choice of a linear least-squares method for model identification. The paper covers elements of the methodology from maneuver design to the completed data base. Major emphasis is placed on the use of state estimation with tracking data to ensure consistency among maneuver variables prior to their entry into the data base. The design and processing of a typical maneuver is illustrated

Flight testing a V/STOL aircraft to identify a full-envelope aerodynamic model

Flight-test techniques are being used to generate a data base for identification of a full-envelope aerodynamic model of a V/STOL fighter aircraft, the YAV-8B Harrier. The flight envelope to be modeled includes hover, transition to conventional flight and back to hover, STOL operation, and normal cruise. Standard V/STOL procedures such as vertical takeoff and landings, and short takeoff and landings are used to gather data in the powered-lift flight regime. Long (3 to 5 min) maneuvers which include a variety of input types are used to obtain large-amplitude control and response excitations. The aircraft is under continuous radar tracking; a laser tracker is used for V/STOL operations near the ground. Tracking data are used with state-estimation techniques to check data consistency and to derive unmeasured variables, for example, angular accelerations. A propulsion model of the YAV-8B's engine and reaction control system is used to isolate aerodynamic forces and moments for model identification. Representative V/STOL flight data are presented. The processing of a typical short takeoff and slow landing maneuver is illustrated

Intellectual Property and Its Alternatives: Incentives, Innovation and Ideology

This dissertation examines the ability of intellectual property (IP) and its alternatives to both facilitate and impede innovation. Over the past 30 years there has been both an expansionary IP policy regime marked by significant increases in IP protection and a flourishing of alternatives to IP as digital technologies empower end users to create and disseminate intellectual works. However, it remains unclear as to whether alternatives to IP can mitigate the problems of exclusionary IP rights while also encouraging innovation. This dissertation provides a theoretical framework for analyzing alternatives to IP focusing on the incentives structures utilized, ability to produce innovative outcomes, and the kind of innovation engendered with the aim of identifying which alternatives are substantive alternatives to IP

Supporting Alternative Incentive Mechanisms for Digital Content: A Comparison of Canadian and US Policy

This paper compares the Government of Canada’s copyright focused approach for encouraging the production of digital content with the U.S. Government’s adoption of a range of incentive systems for the production of content through a content analysis of government policy papers. The first part of the paper examines Canadian policy outlined in the Improving Canada’s Digital Advantage consultation paper and the proposed amendments to the Copyright Act (Bill C-32). The paper argues the government is overly reliant on copyright to encourage the production of creative digital content. Though Bill C-32 would expand the definition of fair dealing and create a user generated content exception, the effectiveness of these measures is severely limited by through the proposed protections for technological protection measures. The second part of the paper examines innovative alternatives to copyright that are being promoted by the U.S. government. The Obama Administration’s Open Government Directive not only provides citizens with access to government data, but also calls on federal departments to use prizes to encourage innovative uses of the data. The U.S. National Institutes of Health has taken a leading role in promoting open access publication of research funded with federal monies by requiring deposit of publications resulting from research in the open access repository PubMed Central. The paper concludes by positing that Canada’s digital economy strategy would be strengthened by providing greater federal support for alternatives to intellectual property such as open data and open access and lessening the focus on copyright as an incentive digital content production