There is no tame triangulation of the infinite real Grassmannian

We show that there is no triangulation of the infinite real Grassmannian of k-planes in R^\infty which is nicely situated with respect to the coordinate axes. In terms of matroid theory, this says there is no triangulation of the Grassmannian subdividing the matroid stratification. This is proved by an argument in projective geometry, considering a specific sequence of configurations of points in the plane.Comment: 11 page

A hybrid perturbation-Galerkin technique for partial differential equations

A two-step hybrid perturbation-Galerkin technique for improving the usefulness of perturbation solutions to partial differential equations which contain a parameter is presented and discussed. In the first step of the method, the leading terms in the asymptotic expansion(s) of the solution about one or more values of the perturbation parameter are obtained using standard perturbation methods. In the second step, the perturbation functions obtained in the first step are used as trial functions in a Bubnov-Galerkin approximation. This semi-analytical, semi-numerical hybrid technique appears to overcome some of the drawbacks of the perturbation and Galerkin methods when they are applied by themselves, while combining some of the good features of each. The technique is illustrated first by a simple example. It is then applied to the problem of determining the flow of a slightly compressible fluid past a circular cylinder and to the problem of determining the shape of a free surface due to a sink above the surface. Solutions obtained by the hybrid method are compared with other approximate solutions, and its possible application to certain problems associated with domain decomposition is discussed

The Full Re-Ionization of Helium

Observations of resolved HeII Lyman alpha absorption in spectra of two QSO's suggest that the epoch of helium ionization occurred at z~3. Proximity zones in the spectra of the quasars (z=3.18, 3.285) at 304 A resemble Stromgren spheres, suggesting that the intergalactic medium is only singly ionized in helium. We present models of the proximity effect which include the full physics of the ionization, heating and cooling and an accurately simulated inhomogeneous gas distribution. In these models the underdense intergalactic medium is heated to at least 10,000-20,000 K after cooling to as low as a few 1000 K due to cosmological expansion, with higher temperatures achieved farther away from the quasar due to absorption-hardened ionizing spectra. The quasars turn on for a few times 10^7 years with a fairly steady flux output at 228 A comparable to the 304 A flux output directly observed with HST. The recoveries in the spectra occur naturally due to voids in the IGM and may provide a fairly model-independent probe of the baryon density.Comment: 5 pages, 3 figures, to appear in the proceedings of "After the Dark Ages: When Galaxies were Young (the Universe at 2<z<5)", 9th Annual October Astrophysics Conference in Marylan

Female Sexual Offending: A Neglected Criminal Justice Issue

Scholars, researchers, and law enforcement officers examining child sexual abuse cases are beginning to report that adolescent and adult females are responsible for a growing number of sexual offenses. This new revelation may reveal that justice officials and many in the lay public do not view the gravity of female and male sexual offending equally. This investigation reveals that female sex offending is more common than traditionally thought and is a neglected criminal justice issue. It also shows that until society recognizes that sex offending is not a gendered crime, more cases will escape the attention of the criminal justice system

Concept Mapping to Develop a Framework for Characterizing Electronic Data Capture (EDC) Systems

CTSAs have brought about a push to find better EDC systems, which facilitate translational research. Based on the data management needs of a specific clinical/translational research lab, concept mapping was used to create a framework to evaluate EDCs. After refinement based on a spiral model, including consultations with the UW CTSA and a survey of other CTSAs, the tool was used to characterize EDCs used at CTSA sites across the country

A radar data processing and enhancement system

This report describes the space position data processing system of the NASA Western Aeronautical Test Range. The system is installed at the Dryden Flight Research Facility of NASA Ames Research Center. This operational radar data system (RADATS) provides simultaneous data processing for multiple data inputs and tracking and antenna pointing outputs while performing real-time monitoring, control, and data enhancement functions. Experience in support of the space shuttle and aeronautical flight research missions is described, as well as the automated calibration and configuration functions of the system

Constitutional Rights of Infants and Toddlers to Have Opportunities to Form Secure Attachment with Incarcerated Mothers: Importance of Prison Nurseries

While the number of women is increasing among the prison population, so too is the need to accommodate those who are pregnant and with children. Instead of examining the diminished rights of incarcerated mothers, this paper examines the rights of babies (infants and toddlers) to have opportunities to form a secure attachment with their incarcerated mother. This paper argues this right triggers the government’s affirmative duty to provide prison nurseries. This paper also seeks several aims that include an examination of the issue of prison nurseries, the need for such programs, their history, the constitutional rights of infants and toddlers to have opportunities to form secure attachment with their long-term caregiver, and the policy implications for women or female prisons

Oracle Complexity Reduction for Model-free LQR: A Stochastic Variance-Reduced Policy Gradient Approach

We investigate the problem of learning an $\epsilon$-approximate solution for the discrete-time Linear Quadratic Regulator (LQR) problem via a Stochastic Variance-Reduced Policy Gradient (SVRPG) approach. Whilst policy gradient methods have proven to converge linearly to the optimal solution of the model-free LQR problem, the substantial requirement for two-point cost queries in gradient estimations may be intractable, particularly in applications where obtaining cost function evaluations at two distinct control input configurations is exceptionally costly. To this end, we propose an oracle-efficient approach. Our method combines both one-point and two-point estimations in a dual-loop variance-reduced algorithm. It achieves an approximate optimal solution with only $O\left(\log\left(1/\epsilon\right)^{\beta}\right)$ two-point cost information for $\beta \in (0,1)$