Polarization tunable selective polariton generator

A selective polariton generator (SPG) design, based on surface plasmon antennae principles, is demonstrated to provide a selective light transmission peak. The polarization-sensitive structure selectively generates and transports polaritons of a desired wavelength through a circular subwavelength aperture. By varying the SPG structure around a central nanohole, we are able to control the peak optical transmission wavelengths via the polarization state of the incident photons. We find good agreement between simulations and experimental results

Polarisation and wavelength selective transmission through nanohole structures with multiple grating geometry

Excitation and localization of surface plasmon polariton modes in metal-dielectric structures can be utilized to construct nanophotonic materials and devices with tuneable optical dispersion. We present a selective polariton generator (SPG) device that demonstrates switching of light transmission based on surface plasmon antennae principles. This polarization-sensitive structure selectively generates and transports polaritons of a desired wavelength through subwavelength apertures. Two of these SPGs have been combined around a nanohole into a new, single device that allows polarization and wavelength selective switching of transmission. The multi-state operation is confirmed by experiment results

Optical measurement of acoustic velocity fields

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Where Are They Now? Migration Patterns for Graduates of the University of British Columbia

In an empirical analysis of the migration patterns of University of British Columbia (UBC) graduates, John F. and David F. Helliwell show in their paper how much the situation has changed between the 1960s and the 1990s. Canadian research and graduate education have expanded dramatically, leading many more undergraduates to stay in Canada for their graduate work. According to the Helliwells, this is perhaps the single most important reason why the south-bound flows of bachelor’s graduates has fallen so much from the early 1960s to the 1990s. Consequently, they argue that the resurgence of discussion of a brain drain in the 1990s has much less basis in the data, and probably represents factors specific to certain sectors, such as health spending, research and university financing, where funding support has risen much less rapidly than in the United States. It has also been fuelled to some extent by sharp increases in the numbers in temporary NAFTA visas to Canadians working in the United States, and in part to increasing gaps in salaries and tax rates in the 1990s that favoured high-income earners in the United States, relative to their Canadian counterparts. The UBC graduate data show that over the past five decades there have been continuing reductions in the shares of UBC graduates living in the United States. For all of the large-scale bachelor’s programs the proportion of graduates living in the United States has continued to fall during the 1990s. For the graduate programs, the proportion living outside Canada is and has always been high, reflecting a very international mix of both the student intake and the available career positions. For all degrees, the proportion of 1990s UBC graduates living in the rest of the world is higher than that in the United States. For graduate degrees, the proportion of the graduates subsequently living and working in Canada, and especially in British Columbia, is much higher than the share of Canadian citizens among the incoming students. With respect to the international distribution of those with the highest level of educational aptitude and attainments, as represented by the master’s and PhD graduates of UBC, Canada and British Columbia stand in the middle ground between the United States and the rest of the world. Comparing the citizenship of UBC’s graduate intake with the country of residence of the graduates, the United States is the largest proportionate net recipient (7 per cent U.S. citizen intake, 14 per cent U.S.-resident 1990s PhDs), Canada is the largest recipient in terms of numbers of PhDs (46 per cent Canadian citizen intake, 70 per cent Canadian-resident 1990s PhDs), with students from 100 other countries providing a net flow into Canada and the United States.Canada, United States, Migration, Brain Drain, Brain-drain, Braindrain, Graduates, Temporary Visa, Visas

Forecasting Police Calls during Peak Times for the City of Cleveland

For a period of time, professors from the Cleveland State University worked closely with the City of Cleveland Police Department. This partnership resulted in access to police records cataloging all emergency 911 calls for the city since 1995. Here, we describe forecasting approaches that can be used by the Police Department based on hourly 911 calls in the years 2001 to 2003 throughout the city during peak call time: the third shift during summer months. This case study is appropriate for class discussions in advanced courses in statistics to explore the application of time series analysis techniques

Long distance chiral corrections in B meson amplitudes

We discuss the chiral corrections to f_B and B_B with particular emphasis on determining the portion of the correction that arises from long distance physics. For very small pion and kaon masses all of the usual corrections are truly long distance, while for larger masses the long distance portion decreases. These chiral corrections have been used to extrapolate lattice calculations towards the physical region of lighter masses. We show in particular that the chiral extrapolation is better behaved if only the long distance portion of the correction is used.Comment: 14 pages, 4 figure