Pion Charge Exchange on Deuterium

We investigate quantum corrections to a classical intranuclear cascade simulation of pion single charge exchange on the deuteron. In order to separate various effects the orders of scattering need to be distinguished and, to that end, we develop signals for each order of scattering corresponding to quasi-free conditions. Quantum corrections are evaluated for double scattering and are found to be large. Global agreement with the data is good.Comment: 30 pages, 12 figure

Evaluation of LANDSAT-D Orbit Determination Using a Filter/Smoother (PREFER)

Simulated range and range rate data for five tracking stations were first generated using batch least squares orbit determination (GTDS). Then GTDS was used (in the differential correction mode) to produce a nominal trajectory which was input to PREFER. The GTDS differential correction (DC) run was made using models which differed from those used to produce the simulated data. These model differences were chosen to be fairly realistic approximations to the errors in the models actually used for operational orbit determination. Several different simulation runs were made with different types of model errors in order to determine the sensitivity to these errors. The nominal trajectory and the simulated measurement data were input to PREFER to produce a smoothed ephemeris file. Numerous runs of PREFER were made in which parameters describing the statistics of the model errors were varied. The likelihood function computed by the Kalman filter determined the ""best'' choice of input parameters. There was strong negative correlation between the likelihood function and the errors in the smoothed ephemeris

MANSEE data analysis results

Results of the data reduction and analysis for the Marine Navigation Systems Evaluation Experiment (MANSEE) are presented. Topics discussed include: the MANSEE test; the navigation sensors which were exercised; the ground truth instrumentation and the processing of ground truth data; and the residual statistics for individual navigation sensors. Residuals were calculated by differencing the actual measurements with anticipated measurements computed from the ground truth trajectory. The results obtained by using the SEAMAP program to filter data from the navigation sensors are also presented. The resultant filtered trajectories were differenced with the corresponding ground truth trajectories to obtain navigation position and velocity errors

Geomagnetic modeling by optimal recursive filtering

The results of a preliminary study to determine the feasibility of using Kalman filter techniques for geomagnetic field modeling are given. Specifically, five separate field models were computed using observatory annual means, satellite, survey and airborne data for the years 1950 to 1976. Each of the individual field models used approximately five years of data. These five models were combined using a recursive information filter (a Kalman filter written in terms of information matrices rather than covariance matrices.) The resulting estimate of the geomagnetic field and its secular variation was propogated four years past the data to the time of the MAGSAT data. The accuracy with which this field model matched the MAGSAT data was evaluated by comparisons with predictions from other pre-MAGSAT field models. The field estimate obtained by recursive estimation was found to be superior to all other models

Monte Carlo simulation of baryon and lepton number violating processes at high energies

We report results obtained with the first complete event generator for electroweak baryon and lepton number violating interactions at supercolliders. We find that baryon number violation would be very difficult to establish, but lepton number violation can be seen provided at least a few hundred L violating events are available with good electron or muon identification in the energy range 10 GeV to 1 TeV.Comment: 40 Pages uuencoded LaTeX (20 PostScript figures included), Cavendish-HEP-93/6, CERN-TH.7090/9

Don’t Bow Down

Perpetuating African ancestral customs, Mardi Gras Indians in New Orleans avoid the African American identity crises illuminated by the poetry of the Harlem Renaissance. The poetry of Langston Hughes, Claude McKay and Waring Cuney incorporate W.E.B. DuBois’ double-consciousness theory to reveal the identity issues and ancestral alienation plaguing African Americans at the turn of the twentieth-century. In comparison, unique political and social circumstances in New Orleans allowed enslaved Africans to practice their ancestral customs weekly. The preservation of this heritage fostered a black community in New Orleans rich in traditions, pride and self-conviction. The development of Mardi Gras Indian culture and the allusions to Africa in Harlem poetry reveal the power of ancestry to establish identity

Don’t Bow Down

Perpetuating African ancestral customs, Mardi Gras Indians in New Orleans avoid the African American identity crises illuminated by the poetry of the Harlem Renaissance. The poetry of Langston Hughes, Claude McKay and Waring Cuney incorporate W.E.B. DuBois’ double-consciousness theory to reveal the identity issues and ancestral alienation plaguing African Americans at the turn of the twentieth-century. In comparison, unique political and social circumstances in New Orleans allowed enslaved Africans to practice their ancestral customs weekly. The preservation of this heritage fostered a black community in New Orleans rich in traditions, pride and self-conviction. The development of Mardi Gras Indian culture and the allusions to Africa in Harlem poetry reveal the power of ancestry to establish identity