The phase-mapping method of phase-contrast magnetic resonance angiography is shown to be based on an implicit assumption that the intravoxel velocity distribution is symmetric about its mean velocity. The effect of asymmetric distributions on the accuracy of quantitative average velocity measurements is determined analytically and verified experimentally. An explicit formulation is developed for the estimated average velocity in a voxel as a function of the true average velocity and the asymmetry of the distribution about the true average velocity. Worst-case distributions are determined for unidirectional and bidirectional flow, and the special case of laminar flow is also investigated. Computer simulations and phantom imaging experiments demonstrate the accuracy of the analysis. For voxels with unidirectional flow, the phase-mapping method produces accurate estimates of average velocity, while results for bidirectional flow indicate possible large errors unless the aliasing velocity is increased, which decreases the signal-to-noise ratio in the resultant velocity map image.

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An adaptive nonlinear Kalman-type filter is presented for the restoration of two-dimensional images degraded by general image formation system degradations and additive white noise. A vector difference equation model is used to represent the degradation process. Due to the nonstationarity of an image the object plane distribution function, i.e. the original image, is partitioned into disjoint regions based on the amount of spatial activity in the image. Difference equation models are used to characterize each of the regions of this nonstationary object plane distribution function.Features of the restoration filter include the ability to account for the response of the human visual system to additive noise in the image; a two-dimensional interpolation scheme to improve the estimates of the initial states in each region; and a nearest neighbor algorithm to choose the previous state vector for the state of pixel (i,j).

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The Post-9/11 GI Bill overhauled the educational benefits available to military veterans. Additionally, the Yellow Ribbon Program makes private institutions more affordable to veterans. Consequently, more veterans are seeking undergraduate degrees, and many schools are seeing significant numbers of veterans for the first time. The National Science Foundation (NSF) has recognized that veteran engineers may address shortages in the engineering workforce and has funded projects to develop models for helping veterans make the transition from active duty to successful student. This special session provides a forum for several awardees to describe their work and to engage a larger audience in discussions about engineering education for veterans. The goals for this session are to raise awareness in the engineering education community about the issues facing veteran engineering students, identify issues commonly encountered as veterans transition from service to the classroom, promote the dissemination of results from NSF-supported efforts to support veterans in engineering programs, provide a forum for sharing best practices related to the successful transition of a veteran from the military to engineering programs, and establish relationships between schools with the shared interest of serving military veteran students.

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