The Use of Virtual Reality Training Environments for Procedural Training in Fourth-Generation Airliners

This study examined the effectiveness of using virtual reality training environments for procedural training in fourth-generation airliners. Its goal was to assess whether the training outcomes from a recurrent training course for FAA certificated Airframe and Powerplant (A&P) technicians, which used a Full Flight Simulator (FFS) to deliver and assess training, differed from the same training delivered using a Virtual Reality (VR) device. The study used an experimental design with three groups and two within-group measures of training effectiveness. The control group followed the current training program and was assessed in the FFS, while the second group was trained using a VR device and was subsequently assessed in the FFS. A third group was formed as a subgroup of the second group, and it contained subjects who had prior VR experience. Training effectiveness was assessed using a modified Global Evaluative Assessment of Robotic Skills (GEARS) tool that measured cognitive and psychomotor aspects of learning along with the time to successful task completion. The population sampled for the study were all FAA certificated A&P technicians who were engine-run qualified; a total sample of 100 was used. Ages ranged from 22 to 72 years old, with a mean age among all groups of 40.37 ( SD = 11.50). Four out of 100 participants were female. A&P experience ranged from 1 to 42 years, with a mean experience among all groups of 14.79 years ( SD = 10.34). Engine-run experience ranged from 0 to 35 years, with a mean experience among all groups of 9.01 years ( SD = 8.02). The hypothesis tested was that there is no difference in performance between the three groups. A MANCOVA analysis was performed using the GEARS scores and Time to Completion as variables. There was no significant difference in training effectiveness (GEARS Total Score and Time) based on Training Group (Control, VR, and VR with Experience), F(4,190) = 1.307, p = .269; Wilk’s lambda = .946, partial eta squared = .027, and the null hypothesis was retained. Similar results were returned using individually the cognitive and psychomotor elements of the GEARS assessment. Enginerun Experience was significant in influencing both GEARS Psychomotor Score, F(1, 95) = 5.732, p = .019 and in influencing Time to task completion, F(1, 95) = 9.346, p = .003. Engine run experience was a significant covariate in this study, while overall A&P experience was not. The VR system, as evaluated, was found to provide task performance that is equivalent to that of the traditional training method that used the FFS. Recommendations for future research and ongoing application of the specific experimental methodology are provided

Localized states in the conserved Swift-Hohenberg equation with cubic nonlinearity

The conserved Swift-Hohenberg equation with cubic nonlinearity provides the simplest microscopic description of the thermodynamic transition from a fluid state to a crystalline state. The resulting phase field crystal model describes a variety of spatially localized structures, in addition to different spatially extended periodic structures. The location of these structures in the temperature versus mean order parameter plane is determined using a combination of numerical continuation in one dimension and direct numerical simulation in two and three dimensions. Localized states are found in the region of thermodynamic coexistence between the homogeneous and structured phases, and may lie outside of the binodal for these states. The results are related to the phenomenon of slanted snaking but take the form of standard homoclinic snaking when the mean order parameter is plotted as a function of the chemical potential, and are expected to carry over to related models with a conserved order parameter.Comment: 40 pages, 13 figure

Quantum walks based on an interferometric analogy

There are presently two models for quantum walks on graphs. The "coined" walk uses discrete time steps, and contains, besides the particle making the walk, a second quantum system, the coin, that determines the direction in which the particle will move. The continuous walk operates with continuous time. Here a third model for a quantum walk is proposed, which is based on an analogy to optical interferometers. It is a discrete-time model, and the unitary operator that advances the walk one step depends only on the local structure of the graph on which the walk is taking place. No quantum coin is introduced. This type of walk allows us to introduce elements, such as phase shifters, that have no counterpart in classical random walks. Walks on the line and cycle are discussed in some detail, and a probability current for these walks is introduced. The relation to the coined quantum walk is also discussed. The paper concludes by showing how to define these walks for a general graph.Comment: Latex,18 pages, 5 figure

Quantum walks as a probe of structural anomalies in graphs

We study how quantum walks can be used to find structural anomalies in graphs via several examples. Two of our examples are based on star graphs, graphs with a single central vertex to which the other vertices, which we call external vertices, are connected by edges. In the basic star graph, these are the only edges. If we now connect a subset of the external vertices to form a complete subgraph, a quantum walk can be used to find these vertices with a quantum speedup. Thus, under some circumstances, a quantum walk can be used to locate where the connectivity of a network changes. We also look at the case of two stars connected at one of their external vertices. A quantum walk can find the vertex shared by both graphs, again with a quantum speedup. This provides an example of using a quantum walk in order to find where two networks are connected. Finally, we use a quantum walk on a complete bipartite graph to find an extra edge that destroys the bipartite nature of the graph.Comment: 10 pages, 2 figure