4,332 research outputs found
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
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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
Financial Education and Savings Outcomes in Individual Development Accounts
Individual Development Accounts (IDAs) are subsidized savings accounts. Unlike other subsidized savings accounts such as Individual Retirement Accounts (IRAs) or 401(k) plans, IDAs are targeted to the poor, provide subsidies through matches rather than through tax breaks, and require participants to attend financial education. Participants accrue matches as they save for purposes that build assets that increase long-term well-being and financial self-sufficiency. Matched uses of withdrawals typically include home purchase, post-secondary education, and microenterprise. The purpose of this study is to examine the relationship between the hours of financial education attended by IDA participants and savings outcomes. The data are from the Downpayments on the American Dream Policy Demonstration (ADD). The goal of financial education is to make people more aware of financial choices and possible consequences. IDA programs require financial education, but there is no systematic/scientific evidence that this requirement is essential. As of June 30, 2000, 81 percent of the 2,378 participants in ADD had attended general financial-education classes. Most participants (65 percent) had one to twelve hours of attendance recorded, 16 percent had 13 hours or more, and 14 percent were recorded as having no hours. Mean attendance was 10.4 hours, with a low of zero and a high of 35. To measure the association between attendance at financial education and savings outcomes, we used a Heckman two-step regression in which the first step predicted exit from the IDA program (and thus a high likelihood of a low opportunity for attendance at financial education). The second step predicted average monthly net deposit (AMND) for those participants who did not exit, controlling for length of participation and a wide range of other factors that might affect AMND. These results broadly suggest that between 0 and 12 hours of financial education have large, positive effects on savings (in the range of one dollar of AMND for each hour of general financial education up to 12 hours). After that point, the effects leveled off. Results for asset-specific education were similar. In short, financial education seems to have had large effects on savings outcomes.education, financial literacy, savings incentives,Individual Development Accounts
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
The addition of rituximab to fludarabine and cyclophosphamide improves progression-free survival in patients with previously treated chronic lymphocytic leukemia.
Chronic lymphocytic leukemia (CLL) is the most common form of leukemia in the United States. There has been considerable progress in understanding the biology and treatment of CLL in last 20 years. The introduction of purine analogs (pentostatin, fludarabine, and cladribine) dramatically increased the response rates compared to alkylating agents. Combination chemoimmunotherapy has further improved the overall frequency of response to over 80% in treatment-naĂŻve and over 60% in relapsed/ refractory disease, respectively
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
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Demographic, clinical, and treatment characteristics of the juvenile primary fibromyalgia syndrome cohort enrolled in the Childhood Arthritis and Rheumatology Research Alliance Legacy Registry.
BackgroundTo describe the demographic, clinical, and treatment characteristics of youth diagnosed with juvenile primary fibromyalgia syndrome (JPFS) who are seen in pediatric rheumatology clinics.MethodsInformation on demographics, symptoms, functioning, and treatments recommended and tried were obtained on patients with JPFS as part of a multi-site patient registry (the Childhood Arthritis and Rheumatology Research Alliance Legacy Registry). Data were summarized using descriptive statistics. In a subset of patients completing registry follow-up visits, changes in symptoms, pain, and functioning were evaluated using growth modeling.ResultsOf the 201 patients with JPFS enrolled in the registry, most were Caucasian/White (85%), non-Hispanic (83%), and female (84%). Ages ranged from 9 to 20 years (M = 15.4 + 2.2). The most common symptoms reported were widespread musculoskeletal pain (91%), fatigue (84%), disordered sleep (82%), and headaches (68%). Pain intensity was rated as moderate to severe (M = 6.3 + 2.4/10). Scores on measures of functioning indicated mild to moderate impairment, with males observed to report significantly greater impairments. For the 37% of the initial cohort having follow-up data available, indicators of function and well-being were found to either worsen over time or remain relatively unchanged.ConclusionsThe symptoms of JPFS remained persistent and disabling for many patients treated by pediatric rheumatologists. Further study appears warranted to elucidate gender differences in the impact of JPFS symptoms. Work also is needed to identify accessible and effective outpatient treatment options for JPFS that can be routinely recommended or implemented by pediatric rheumatology providers
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
Transforming Schools Using Project-Based Learning, Performance Assessment, and Common Core Standards
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