Enforcement and Spectrum Sharing: Case Studies of Federal-Commercial Sharing

To promote economic growth and unleash the potential of wireless broadband, there is a need to introduce more spectrally efficient technologies and spectrum management regimes. That led to an environment where commercial wireless broadband need to share spectrum with the federal and non-federal operations. Implementing sharing regimes on a non-opportunistic basis means that sharing agreements must be implemented. To have meaning, those agreements must be enforceable.\ud \ud With the significant exception of license-free wireless systems, commercial wireless services are based on exclusive use. With the policy change facilitating spectrum sharing, it becomes necessary to consider how sharing might take place in practice. Beyond the technical aspects of sharing, that must be resolved lie questions about how usage rights are appropriately determined and enforced. This paper is reasoning about enforcement in a particular spectrum bands (1695-1710 MHz and 3.5 GHz) that are currently being proposed for sharing between commercial services and incumbent spectrum users in the US. We examine three enforcement approaches, exclusion zones, protection zones and pure ex post and consider their implications in terms of cost elements, opportunity cost, and their adaptability

Hereditary Polytopes

Every regular polytope has the remarkable property that it inherits all symmetries of each of its facets. This property distinguishes a natural class of polytopes which are called hereditary. Regular polytopes are by definition hereditary, but the other polytopes in this class are interesting, have possible applications in modeling of structures, and have not been previously investigated. This paper establishes the basic theory of hereditary polytopes, focussing on the analysis and construction of hereditary polytopes with highly symmetric faces.Comment: Discrete Geometry and Applications (eds. R.Connelly and A.Ivic Weiss), Fields Institute Communications, (23 pp, to appear

In-Situ Educational Research from Concept to Classroom Implementation: A Multiple Paper Dissertation

An educational researcher sought to collaborate with a classroom instructor to introduce problem-based learning as a new teaching intervention. First, a classroom instructor was approached to consider how a problem-based learning instructional approach might fit with their existing curriculum plan. The researcher and the classroom teacher used a discussion framework to decide together how to best design a professional learning course meant to prepare the teacher to use the new techniques in their classroom. The teacher took the professional learning course and subsequently designed his own problem-based learning course. That course was then delivered to undergraduate students in a college senior thermo-fluids lab course. Quantitative and qualitative data describe how students recognized the connection between the lab course and their perceptions of a future career as engineers. Preliminary findings suggest the researcher and teacher professional learning codesign process contributed positively to the classroom teachers developing and delivering their own PBL course that was perceived by students to contribute positively to their content knowledge, motivation and perception of their future career as engineers

2009-2010 Mark Kaplan and Yael Weiss in Recital: All Brahms Concert

Mark Kaplan Master Class (November 30, 2009) - Program Yael Weiss Master Class (December 4, 2009) - Progra

Combined Error Correction Techniques for Quantum Computing Architectures

Proposals for quantum computing devices are many and varied. They each have unique noise processes that make none of them fully reliable at this time. There are several error correction/avoidance techniques which are valuable for reducing or eliminating errors, but not one, alone, will serve as a panacea. One must therefore take advantage of the strength of each of these techniques so that we may extend the coherence times of the quantum systems and create more reliable computing devices. To this end we give a general strategy for using dynamical decoupling operations on encoded subspaces. These encodings may be of any form; of particular importance are decoherence-free subspaces and quantum error correction codes. We then give means for empirically determining an appropriate set of dynamical decoupling operations for a given experiment. Using these techniques, we then propose a comprehensive encoding solution to many of the problems of quantum computing proposals which use exchange-type interactions. This uses a decoherence-free subspace and an efficient set of dynamical decoupling operations. It also addresses the problems of controllability in solid state quantum dot devices.Comment: Contribution to Proceedings of the 2002 Physics of Quantum Electronics Conference", to be published in J. Mod. Optics. This paper provides a summary and review of quant-ph/0205156 and quant-ph/0112054, and some new result

Implementation of a flexible frequency-invariant broadband beamformer based on fourier properties

Aperture and operating frequency of a beamformer are generally proportional to its resolution, and inversely proportional to its beamwidth. This paper addresses the design and implementation of a beamformer with a frequency-dependent limitation of its aperture such that the frequency-dependence of its resolution is eliminated. Operating across a number of octaves, firstly an octave-invariance design is achieved by means of a nested array structure. Secondly, within each octave, a frequency-dependent aperture control then removes the remaining frequency-dependency. By exploiting Fourier properties and correspondences between coefficient and beamspace, we show that this design is exact, and can accommodate the inclusion of arbitrary shading and different look directions

Antisocial behaviour and violent delinquency among boys with a migration background: A German panel study

Immigrant boys show higher rates of antisocial behaviour. However, results of previous studies showed some contradictory findings in terms of intercultural differences in antisocial behaviour. In our study, we used an intercultural comparison of antisocial behaviour based on two different definitions of migration status (nationality vs. migration background). According to migration background, however not according to nationality, significant but small differences were found only in violent delinquency. A longitudinal mediator model based on the disintegration approach (Anhut & Heitmeyer, 2000) was examined in order to contribute to our understanding of the background of violent delinquency in immigrant boys. The data were from a German panel study conducted in the cities of Dortmund and Nuremberg. The results of the mediator model showed that perceived discrimination and negative parenting affect violent delinquency indirectly through violence attitudes, self-control, and peer delinquency. The findings suggest that preventive measures against violent delinquency should focus on these indirect effects and migrant-specific variables.2-s2.0-8507790622