5,167 research outputs found

    Fine Tuning the Federal Government\u27s Role in Public Broadcasting

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    The Public Broadcasting Act of 1967 represented a major effort by the federal government to provide entertaining and enlightening programming unlike that being offered by major broadcasters. Central to this effort was the creation of the Corporation for Public Broadcasting (CPB), an independent corporation whose mission was to facilitate diversity, creativity, and innovation in noncommercial public broadcasting. It was to achieve this goal without engaging in content control over programming. However, members of Congress have expressed concern over the types of programming CPB was funding. As a result, Congress in 1992 directed the CPB to define national programming standards for public broadcasting. The CPB was also directed to monitor stations\u27 compliance with these standards and to condition future grant receipts on adequate compliance. The Author argues that CPB\u27s enforcement of these programming standards infringes on the local stations\u27 freedom of speech and restricts their ability to program for their local communities. The Author argues that CPB\u27s role should be to provide grants for national programming to fill the gaps in the services offered by public broadcasting entities rather than dictate a national standard for programming

    Introduction of the Keynote Presentation on First Amendment & Regulatory Concerns by Floyd Abrams

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    Generation of mechanical interference fringes by multi-photon counting

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    Exploring the quantum behaviour of macroscopic objects provides an intriguing avenue to study the foundations of physics and to develop a suite of quantum-enhanced technologies. One prominent path of study is provided by quantum optomechanics which utilizes the tools of quantum optics to control the motion of macroscopic mechanical resonators. Despite excellent recent progress, the preparation of mechanical quantum superposition states remains outstanding due to weak coupling and thermal decoherence. Here we present a novel optomechanical scheme that significantly relaxes these requirements allowing the preparation of quantum superposition states of motion of a mechanical resonator by exploiting the nonlinearity of multi-photon quantum measurements. Our method is capable of generating non-classical mechanical states without the need for strong single photon coupling, is resilient against optical loss, and offers more favourable scaling against initial mechanical thermal occupation than existing schemes. Moreover, our approach allows the generation of larger superposition states by projecting the optical field onto NOON states. We experimentally demonstrate this multi-photon-counting technique on a mechanical thermal state in the classical limit and observe interference fringes in the mechanical position distribution that show phase superresolution. This opens a feasible route to explore and exploit quantum phenomena at a macroscopic scale.Comment: 16 pages, 4 figures. v1: submitted for review on 28 Jan 2016. v2: significantly revised manuscript. v3: some further revisions and some extra results included. v3: new results added, extra author added, close to published version, supplementary material available with published versio

    The Role of GIS to Enable Public-Sector Decision Making Under Conditions of Uncertainty

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    Uncertainty is inherent in environmental planning and decision making. For example, water managers in arid regions are attuned to the uncertainty of water supply due to prolonged periods of drought. To contend with multiple sources and forms of uncertainty, resource managers implement strategies and tools to aid in the exploration and interpretation of data and scenarios. Various GIS capabilities, such as statistical analysis, modeling and visualization are available to decision makers who face the challenge of making decisions under conditions of deep uncertainty. While significant research has lead to the inclusion and representation of uncertainty in GIS, existing GIS literature does not address how decision makers implement and utilize GIS as an assistive technology to contend with deep uncertainty. We address this gap through a case study of water managers in the Phoenix Metropolitan Area, examining how they engage with GIS in making decisions and coping with uncertainty. Findings of a qualitative analysis of water mangers reveal the need to distinguish between implicit and explicit uncertainty. Implicit uncertainty is linked to the decision-making process, and while understood, it is not displayed or revealed separately from the data. In contrast, explicit uncertainty is conceived as separate from the process and is something that can be described or displayed. Developed from twelve interviews with Phoenix-area water managers in 2005, these distinctions of uncertainty clarify the use of GIS in decision making. Findings show that managers use the products of GIS for exploring uncertainty (e.g., cartographic products). Uncertainty visualization emerged as a current practice, but definitions of what constitutes such visualizations were not consistent across decision makers. Additionally, uncertainty was a common and even sometimes helpful element of decision making; rather than being a hindrance, it is seen as an essential component of the process. These findings contradict prior research relating to uncertainty visualization where decision makers often express discomfort with the presence of uncertainty.

    The effect of farming system on dairy cow cleanliness in the UK and implications to udder health

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    The cleanliness of dairy cows was assessed using a 20 point hygiene score system at different times in the year on 14 organic and 14 conventional farms in the UK. Overall, cows were dirtier during winter housing compared to summer grazing. Farming system had no effect on cow cleanliness when cows were at grass, but when housed in the winter, organic cows were more likely to be cleaner. There was a link between cow hygiene scores and milk hygiene, with herds having lower bulk tank somatic cell counts (BTSCC) tending to have cleaner cows. This relationship was strongest for the organic herds. There was no significant link between hygiene score and Bactoscan (BS) count or mastitis incidence

    Impurity transport, turbulence transitions and intrinsic rotation in Alcator C-Mod plasmas

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    Linear and nonlinear gyrokinetic simulations are used to probe turbulent impurity transport in intrinsically rotating tokamak plasmas. For this simulation-based study, experimental input parameters are taken from a pair of ICRF heated Alcator C-Mod discharges exhibiting a change in the sign of the normalized toroidal rotation gradient at mid-radius (i.e. a change from hollow to peaked intrinsic rotation profiles). The simulations show that there is no change in the peaking of the calcium impurity between the plasmas with peaked and hollow rotation profiles, suggesting that the impurity transport and the shape of the rotation do not always change together. Furthermore, near mid-radius, r/a = 0.5 (normalized midplane minor radius), the linear and nonlinear gyrokinetic simulations exhibit no evidence of a transition from ion temperature gradient (ITG) to trapped electron mode dominance when the intrinsic rotation profile changes from peaked to hollow. Extensive nonlinear sensitivity analysis is performed, and there is no change in the ITG critical gradient or in the stiffness of ion heat transport with the change in the intrinsic toroidal rotation profile shape, which suggests that the shape of the rotation profile is not dominated by the ITG onset in these cases.United States. Department of Energy (contract DE-FC02-99ER54512-CMOD)United States. Department of Energy (Fusion Energy Postdoctoral Research Program

    Quantum Hypercube States

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    We introduce quantum hypercube states, a class of continuous-variable quantum states that are generated as orthographic projections of hypercubes onto the quadrature phase-space of a bosonic mode. In addition to their interesting geometry, hypercube states display phase-space features much smaller than Planck's constant, and a large volume of Wigner-negativity. We theoretically show that these features make hypercube states sensitive to displacements at extremely small scales in a way that is surprisingly robust to initial thermal occupation and to small separation of the superposed state-components. In a high-temperature proof-of-principle optomechanics experiment we observe, and match to theory, the signature outer-edge vertex structure of hypercube states.Comment: Main consists of 5 pages and 5 figures. Supplementary material consists of 5 pages and 6 figure

    Kang-Redner Anomaly in Cluster-Cluster Aggregation

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    The large time, small mass, asymptotic behavior of the average mass distribution \pb is studied in a dd-dimensional system of diffusing aggregating particles for 1d21\leq d \leq 2. By means of both a renormalization group computation as well as a direct re-summation of leading terms in the small reaction-rate expansion of the average mass distribution, it is shown that \pb \sim \frac{1}{t^d} (\frac{m^{1/d}}{\sqrt{t}})^{e_{KR}} for mtd/2m \ll t^{d/2}, where eKR=ϵ+O(ϵ2)e_{KR}=\epsilon +O(\epsilon ^2) and ϵ=2d\epsilon =2-d. In two dimensions, it is shown that \pb \sim \frac{\ln(m) \ln(t)}{t^2} for mt/ln(t) m \ll t/ \ln(t). Numerical simulations in two dimensions supporting the analytical results are also presented.Comment: 11 pages, 6 figures, Revtex
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