5,133 research outputs found

    Becoming physical education: the ontological shift to complexity

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    In this paper, we present the view that an ontological shift to complexitythinking will be significant in the future of physical education (PE). Complexity thinking not only moves PE beyond long dominant modernist approaches but also offers the opportunity to integrate many of the postmodern perspectives that currently seek to frame PE. Four interconnected complexity commonalities, becoming, lived time, selforganisation and boundaries, are presented in an overarching frame to guide future PE developments in ways that are coherent, connected and emergent. PE is subsequently viewed as a complex phenomenon that is always in a non-linear, messy and never-ending process of becoming. Students, teachers and other stakeholders are also complex as their past, present and future experiences constantly merge in a lived time unity to create lifelong and life-wide PE journeys that are both personalised and holistic. Central to these personalised journeys is each stakeholder’s ability to self-organise and influence the trajectory of their pathways. Self-organisation, however, is not a relativist ‘anything goes’ phenomenon but a process that takes place within a multiplicity of boundaries. While boundaries may traditionally be viewed as divisive features, complexity thinking recognises that many boundaries are flexible and enable the creation of ‘boundary spaces’ in which ‘rich’ discussions can take place to develop more coherent, connected and emergent forms of PE. Transdisciplinary Inquiry (TDI) and Ecologically Informed Practice (EIP) are presented as perspectives that can help teachers, and others, create the ‘boundary spaces’ in which ways to plan and introduce complexity-informed forms of PE can be explored. The paper concludes by proposing that the challenge for PE in the future will be for practitioners to develop the adaptability, openness, confidence and self-organising skills that will be needed to make the most effective use of the ‘rich interactions’ that these ‘boundary spaces’ offer

    Two-Band-Type Superconducting Instability in MgB2

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    Using the tight-binding method for the π\pi-bands in MgB2_2, the Hubbard on-site Coulomb interaction on two inequivalent boron pzp_z-orbitals is transformed into expressions in terms of π\pi-band operators. For scattering processes relevant to the problemin which a wave vector {\bf q} is parallel to z^\hat{z}, it is found to take a relatively simple form consisting of intra-band Coulomb scattering, interband pair scattering etc. with large constant coupling constants. This allows to get a simple expression for the amplitude of interband pair scattering between two π\pi-bands, which diverges if the interband polarization function in it becomes large enough.The latter was approximately evaluated and found to be largely enhanced in the band structure in MgB2_2. These results lead to a divergent interband pair scattering, meaning two-band-type superconducting instability with enhanced TcT_c. Adding a subsidiary BCS attractive interaction in each band into consideration, a semi-quantitative gap equation is given, and TcT_c and isotope exponent α\alpha are derived. The present instability is asserted to be the origin of high TcT_c in MgB2_2.Comment: 4 pages, to be published in J. Phys. Soc. Jpn. vol. 70, No.

    Preoperative systemic inflammation predicts postoperative infectious complications in patients undergoing curative resection for colorectal cancer

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    The presence of systemic inflammation before surgery, as evidenced by the glasgow prognostic score (mGPS), predicts poor long-term survival in colorectal cancer. The aim was to examine the relationship between the preoperative mGPS and the development of postoperative complications in patients undergoing potentially curative resection for colorectal cancer. Patients (n=455) who underwent potentially curative resections between 2003 and 2007 were assessed consecutively, and details were recorded in a database. The majority of patients presented for elective surgery (85%) were over the age of 65 years (70%), were male (58%), were deprived (53%), and had TNM stage I/II disease (61%), had preoperative haemoglobin (56%), white cell count (87%) and mGPS 0 (58%) in the normal range. After surgery, 86 (19%) patients developed a postoperative complication; 70 (81%) of which were infectious complications. On multivariate analysis, peritoneal soiling (P<0.01), elevated preoperative white cell count (P<0.05) and mGPS (P<0.01) were independently associated with increased risk of developing a postoperative infection. In elective patients, only the mGPS (OR=1.75, 95% CI=1.17-2.63, P=0.007) was significantly associated with increased risk of developing a postoperative infection. Preoperative elevated mGPS predicts increased postoperative infectious complications in patients undergoing potentially curative resection for colorectal cancer

    Random Fixed Point of Three-Dimensional Random-Bond Ising Models

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    The fixed-point structure of three-dimensional bond-disordered Ising models is investigated using the numerical domain-wall renormalization-group method. It is found that, in the +/-J Ising model, there exists a non-trivial fixed point along the phase boundary between the paramagnetic and ferromagnetic phases. The fixed-point Hamiltonian of the +/-J model numerically coincides with that of the unfrustrated random Ising models, strongly suggesting that both belong to the same universality class. Another fixed point corresponding to the multicritical point is also found in the +/-J model. Critical properties associated with the fixed point are qualitatively consistent with theoretical predictions.Comment: 4 pages, 5 figures, to be published in Journal of the Physical Society of Japa

    A simple abstraction of arrays and maps by program translation

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    We present an approach for the static analysis of programs handling arrays, with a Galois connection between the semantics of the array program and semantics of purely scalar operations. The simplest way to implement it is by automatic, syntactic transformation of the array program into a scalar program followed analysis of the scalar program with any static analysis technique (abstract interpretation, acceleration, predicate abstraction,.. .). The scalars invariants thus obtained are translated back onto the original program as universally quantified array invariants. We illustrate our approach on a variety of examples, leading to the " Dutch flag " algorithm

    Radar systems for the water resources mission, volume 2

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    The application of synthetic aperture radar (SAR) in monitoring and managing earth resources was examined. The function of spaceborne radar is to provide maps and map imagery to be used for earth resource and oceanographic applications. Spaceborne radar has the capability of mapping the entire United States regardless of inclement weather; however, the imagery must have a high degree of resolution to be meaningful. Attaining this resolution is possible with the SAR system. Imagery of the required quality must first meet mission parameters in the following areas: antenna patterns, azimuth and range ambiguities, coverage, and angle of incidence

    Radar systems for the water resources mission. Volume 4: Appendices E-I

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    The use of a scanning antenna beam for a synthetic aperture system was examined. When the resolution required was modest, the radar did not use all the time the beam was passing a given point on the ground to build a synthetic aperture, so time was available to scan the beam to other positions and build several images at different ranges. The scanning synthetic-aperture radar (SCANSAR) could achieve swathwidths of well over 100 km with modest antenna size. Design considerations for a SCANSAR for hydrologic parameter observation are presented. Because of the high sensitivity to soil moisture at angles of incidence near vertical, a 7 to 22 deg swath was considered for that application. For snow and ice monitoring, a 22 to 37 deg scan was used. Frequencies from X-band to L-band were used in the design studies, but the proposed system operated in C-band at 4.75 GHz. It achieved an azimuth resolution of about 50 meters at all angles, with a range resolution varying from 150 meters at 7 deg to 31 meters at 37 deg. The antenna required an aperture of 3 x 4.16 meters, and the average transmitter power was under 2 watts

    Radar systems for the water resources mission, volume 1

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    The state of the art determination was made for radar measurement of: soil moisture, snow, standing and flowing water, lake and river ice, determination of required spacecraft radar parameters, study of synthetic-aperture radar systems to meet these parametric requirements, and study of techniques for on-board processing of the radar data. Significant new concepts developed include the following: scanning synthetic-aperture radar to achieve wide-swath coverage; single-sideband radar; and comb-filter range-sequential, range-offset SAR processing. The state of the art in radar measurement of water resources parameters is outlined. The feasibility for immediate development of a spacecraft water resources SAR was established. Numerous candidates for the on-board processor were examined

    Radar systems for a polar mission, volume 3, appendices A-D, S, T

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    Success is reported in the radar monitoring of such features of sea ice as concentration, floe size, leads and other water openings, drift, topographic features such as pressure ridges and hummocks, fractures, and a qualitative indication of age and thickness. Scatterometer measurements made north of Alaska show a good correlation with a scattering coefficient with apparent thickness as deduced from ice type analysis of stereo aerial photography. Indications are that frequencies from 9 GHz upward seem to be better for sea ice radar purposes than the information gathered at 0.4 GHz by a scatterometer. Some information indicates that 1 GHz is useful, but not as useful as higher frequencies. Either form of like-polarization can be used and it appears that cross-polarization may be more useful for thickness measurement. Resolution requirements have not been fully established, but most of the systems in use have had poorer resolution than 20 meters. The radar return from sea ice is found to be much different than that from lake ice. Methods to decrease side lobe levels of the Fresnel zone-plate processor and to decrease the memory requirements of a synthetic radar processor are discussed
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