Handling Qualities Evaluation of a Supersonic Tailless Air Vehicle

This thesis presents the results of a handling qualities evaluation of a supersonic tailless air vehicle. The 2006 Quadrennial Defense Review mandated the need for the next generation of long-range strike aircraft by 2018. Due to speed and stealth requirements, this resulted in a tailless aircraft with an instantaneous center of rotation located well forward of that of a conventional aircraft. This thesis examines how this center of rotation affected pilot handling qualities ratings. This effect should have been the most pronounced during approach and landing, and was where the testing focused. The goal of this research was to develop a systematic procedure for evaluating the handling qualities of this aircraft, and to determine how different pilot flying techniques or pilot-inceptor interactions influenced them. This procedure was demonstrated in simulator testing and in flight testing on the Calspan-operated Total In-Flight Simulator aircraft

Evaluation of Concurrent Operant Preference Assessment For Identification of Social Consequences in Adolescents: Daily Living Skills in a Residential Setting

There are a growing number of youth in residential care who are dually diagnosed with a mental health disorder and developmental delay. By using function-based interventions, individuals\u27 problem behaviors may be addressed without requiring a higher level of care. An alternative strategy to a functional analysis is to use a concurrent operant preference assessment (COA) to determine the individual\u27s preferred consequences and allow appropriate interventions to be developed based on the preferred consequence and potential function of the challenging behavior for the individual. The clinical utility of a COA procedure to increase latency to compliance with daily living skills with youth dually diagnosed in a residential setting was evaluated using a multiple baseline across subjects design. Results showed that the use of potential reinforcers determined by the COA increased compliance with daily living skills with all 5 participants. Additionally, these skills were maintained at a 2 week probe

Superstructures on graded phase space

In this thesis we study problems associated with the generalisation, to include Grassmann type variables, of the 'group theoretical' approach to quantisation of C.Isham [37]. Although a full generalisation of this quantisation scheme is not achieved, consideration of this problem leads us to make studies in four principle sectors: (A) Graded Poisson brackets and graded 'vector field like’ constructs. A graded version of the Hamiltonian vector field is defined and it is found that both left acting and right acting vector fields are necessary. Properties of these vector fields are investigated. (B) Local graded canonical transformations and graded function groups. Simple examples of these structures are studied. (C) The realisation of a general superalgebra by the use of graded 'functions' and the graded Poisson bracket. The graded generalisation of a standard classical result is presented. Also the - question of central, extensions to these algebras is studied and a partial generalisation of a classical result on this is given. (D) Investigations into a model of quantum mechanics on a2-sphere which incorporates fermions. This model is similarto that derived by Spiegelglas [56] and Barcelos-Neto et al.[6,7]from the 0(3) supersymmetrie sigma model first studied by Witten in [62,63], except that an additional primary constraint has been included. The graded Dirac brackets of this model are calculated

Parallel implementation of an optimal two level additive Schwarz preconditioner for the 3-D finite element solution of elliptic partial differential equations

This paper presents a description of the extension and parallel implementation of a new two level additive Schwarz (AS) preconditioner for the solution of 3-D elliptic partial differential equations (PDEs). This preconditioner, introduced in Bank et al. (SIAM J. Sci. Comput. 2002; 23: 1818), is based upon the use of a novel form of overlap between the subdomains which makes use of a hierarchy of meshes: with just a single layer of overlapping elements at each level of the hierarchy. The generalization considered here is based upon the restricted AS approach reported in (SIAM J. Sci. Comput. 1999; 21: 792) and the parallel implementation is an extension of work in two dimensions (Concurrency Comput. Practice Experience 2001; 13: 327)

Parallel application of a novel domain decomposition preconditioner for the adaptive finite-element solution of three-dimensional convection-dominated PDEs

We describe and analyse the parallel implementation of a novel domain decomposition preconditioner for the fast iterative solution of linear systems of algebraic equations arising from the discretization of elliptic partial differential equations (PDEs) in three dimensions. In previous theoretical work, this preconditioner has been proved to be optimal for symmetric positive-definite (SPD) linear systems. In this paper, we provide details of our three-dimensional parallel implementation and demonstrate that the technique may be generalized to the solution of non-symmetric algebraic systems, such as those arising when convection-diffusion problems are discretized using either Galerkin or stabilized finite-element methods (FEMs). Furthermore, we illustrate the potential of the preconditioner for use within an adaptive finite-element framework by successfully solving convection-dominated problems on locally, rather than globally, refined meshes

Locally optimal unstructured finite element meshes in 3 dimensions

This paper investigates the adaptive finite element solution of a general class of variational problems in three dimensions using a combination of node movement, edge swapping, face swapping and node insertion. The adaptive strategy proposed is a generalization of previous work in two dimensions and is based upon the construction of a hierarchy of locally optimal meshes. Results presented, both for a single equation and a system of coupled equations, suggest that this approach is able to produce better meshes of tetrahedra than those obtained by more conventional adaptive strategies and in a relatively efficient manner

A comparison of some dynamic load-balancing algorithms for a parallel adaptive flow solver

In this paper we contrast the performance of a number of different parallel dynamic load-balancing algorithms when used in conjunction with a particular parallel, adaptive, time-dependent, 3D flow solver. An overview of this solver is given along with a description of the dynamic load-balancing problem that results from its use. Two recently published parallel dynamic load-balancing software tools are then briefly described and a number of recursive parallel dynamic load-balancing techniques are also outlined. The effectiveness of each of these algorithms is then assessed when they are coupled with the parallel adaptive solver and used to tackle a model 3D flow problem

A new parallel domain decomposition method for the adaptive finite element solution of elliptic partial differential equations

We present a new domain decomposition algorithm for the parallel finite element solution of elliptic partial differential equations. As with most parallel domain decomposition methods each processor is assigned one or more subdomains and an iteration is devised which allows the processors to solve their own subproblem(s) concurrently. The novel feature of this algorithm however is that each of these subproblems is defined over the entire domain - although the vast majority of the degrees of freedom for each subproblem are associated with a single subdomain (owned by the corresponding processor). This ensures that a global mechanism is contained within each of the subproblems tackled and so no separate coarse grid solve is required in order to achieve rapid convergence of the overall iteration. Furthermore, by following the paradigm introduced in [15], it is demonstrated that this domain decomposition solver may be coupled easily with a conventional mesh refinement code, thus allowing the accuracy, reliability and efficiency of mesh adaptivity to be utilized in a well load-balanced manner. Finally, numerical evidence is presented which suggests that this technique has significant potential, both in terms of the rapid convergence properties and the efficiency of the parallel implementation

An adaptive finite element procedure for fully-coupled point contact elastohydrodynamic lubrication problems

This paper presents an automatic locally adaptive finite element solver for the fully-coupled EHL point contact problems. The proposed algorithm uses a posteriori error estimation in the stress in order to control adaptivity in both the elasticity and lubrication domains. The implementation is based on the fact that the solution of the linear elasticity equation exhibits large variations close to the fluid domain on which the Reynolds equation is solved. Thus the local refinement in such region not only improves the accuracy of the elastic deformation solution significantly but also yield an improved accuracy in the pressure profile due to increase in the spatial resolution of fluid domain. Thus, the improved traction boundary conditions lead to even better approximation of the elastic deformation. Hence, a simple and an effective way to develop an adaptive procedure for the fully-coupled EHL problem is to apply the local refinement to the linear elasticity mesh. The proposed algorithm also seeks to improve the quality of refined meshes to ensure the best overall accuracy. It is shown that the adaptive procedure effectively refines the elements in the region(s) showing the largest local error in their solution, and reduces the overall error with optimal computational cost for a variety of EHL cases. Specifically, the computational cost of proposed adaptive algorithm is shown to be linear with respect to problem size as the number of refinement levels grows