589 research outputs found

    A characterization of Schauder frames which are near-Schauder bases

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    A basic problem of interest in connection with the study of Schauder frames in Banach spaces is that of characterizing those Schauder frames which can essentially be regarded as Schauder bases. In this paper, we give a solution to this problem using the notion of the minimal-associated sequence spaces and the minimal-associated reconstruction operators for Schauder frames. We prove that a Schauder frame is a near-Schauder basis if and only if the kernel of the minimal-associated reconstruction operator contains no copy of c0c_0. In particular, a Schauder frame of a Banach space with no copy of c0c_0 is a near-Schauder basis if and only if the minimal-associated sequence space contains no copy of c0c_0. In these cases, the minimal-associated reconstruction operator has a finite dimensional kernel and the dimension of the kernel is exactly the excess of the near-Schauder basis. Using these results, we make related applications on Besselian frames and near-Riesz bases.Comment: 12 page

    Grid-Enabled Non-Invasive Blood Glucose Measurement

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    Abstract. Earth and life sciences are at the forefront to successfully include computational simulations and modeling. Medical applications are often mentioned as the killer applications for the Grid. The complex methodology and models of Traditional Chinese Medicine offer different approaches to diagnose and treat a persons health condition than typical Western medicine. A possibility to make this often hidden knowledge ex-plicit and available to a broader audience will result in mutual synergies for Western and Chinese medicine as well as improved patient care. This paper proposes the design and implementation of a method to accurately estimate blood glucose values using a novel non-invasive method based on electro-transformation measures in human body meridians. The frame-work used for this scientific computing collaboration, namely the China-Austria Data Grid (CADGrid) framework, provides an Intelligence Base offering commonly used models and algorithms as Web/Grid-Services. The controlled execution of the Non-Invasive Blood Glucose Measure-ment Service and the management of scientific data that arise from model execution can be seen as the first application on top of the CADGrid

    Features and design intent in engineering sketches

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    We investigate the problem of determining design intent from engineering sketches: what did the designer have in mind when sketching a component? Specifically, we consider the unidirectional reverse mapping from form features, as determined from an input sketch, to design features, representing the design intent present in the designer’s mind. We introduce a list of com- mon engineering form features. For each, we list which geometrical cues may be helpful in identifying these features in design sketches, and we list the design features which such form features commonly imply. We show that a reductionist approach which decomposes a diagram into form features can be used to deduce the design intent of the object portrayed in a drawing. We supply experimental results in support of this idea

    Baryon number violation, baryogenesis and defects with extra dimensions

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    In generic models for grand unified theories(GUT), various types of baryon number violating processes are expected when quarks and leptons propagate in the background of GUT strings. On the other hand, in models with large extra dimensions, the baryon number violation in the background of a string is not trivial because it must depend on the mechanism of the proton stabilization. In this paper we argue that cosmic strings in models with extra dimensions can enhance the baryon number violation to a phenomenologically interesting level, if the proton decay is suppressed by the mechanism of localized wavefunctions. We also make some comments on baryogenesis mediated by cosmological defects. We show at least two scenarios will be successful in this direction. One is the scenario of leptogenesis where the required lepton number conversion is mediated by cosmic strings, and the other is the baryogenesis from the decaying cosmological domain wall. Both scenarios are new and have not been discussed in the past.Comment: 20pages, latex2e, comments and references added, to appear in PR

    Chinese degraded grasslands – pathways for sustainability

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    The 400 m ha of grazing lands in China, mainly across the north and west of the country, have similar problems to those throughout the steppe of Mongolia, Central Asia and neighbouring countries. The grasslands are in drier regions (50–500 mm) across mainly Inner Mongolia, Xinjiang, Tibet, Qinghai, Gansu and Sichuan, often at higher altitudes on the Tibetan, Mongolian and Loess Plateaus, and have for millennia supported the livelihoods of millions of herders. By 2002, surveys were classifying 90% of the grasslands as degraded. Less than 10% were considered desertified to the extent that replanting was the only option to restore some plant cover. The majority of the grasslands were considered capable of being rehabilitated to some degree through changing management practices. In the 1980s the first Grassland Laws were promulgated, initiating a series of programs aimed at rehabilitating the grasslands. These programs included the establishment of individual ‘user rights’ to herders to use a defined area of grassland and the imposition of grazing bans, often for five years, to rehabilitate degraded areas. These were often applied at a regional level. At the same time, herders were encouraged to have more livestock as that was seen as a pathway to lift them from poverty. The sheep equivalent of grazing animals for the whole of China, has increased 4-fold since 1949, often by greater amounts in some regions. But there was very limited work done on how best to manage grazing livestock in ways that could aid grassland rehabilitation. In the early 2000s a collaborative program was started between several Australian and Chinese Institutes, to investigate better ways of rehabilitating the grasslands and to improve herder incomes from livestock. This work involved the development of four models that could use the limited data available, to help guide a series of research programs. These models indicated that halving stocking rates could maintain or increase herder net incomes. Farm demonstrations showed this result applied in practice and grasslands did improve. A series of grazing experiments found that halving the current stocking rates was needed to enable the survival of the better plant species within the grassland. A model that estimated the net value of each animal indicated that often half the animals were generating marginal or negative incomes, and could be culled without affecting the household income, again substantiated in farm demonstrations. In this paper, the causes of degradation, which can be traced back to the progressive changes that have occurred in China since 1949, are discussed together with the practice changes that have come from a large collaborative research program between Australia and China. Efficient markets and land tenure reform are needed to help create the incentives for herders to change in sustainable ways

    Effects of oxygen adsorption on carbon nanotube field emitters

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    Effects of oxygen adsorption on the field emission of carbon nanotubes are studied through first-principles calculations. Calculated emission currents are significantly enhanced when oxygen is adsorbed at the tip and the underlying physics is explained in terms of the change in the electronic structure by oxidation and the local field increase at the adsorption site. The issue of the current degradation accompanied by the oxidative etching is also addressed. The field-emission-microscopy images on the phosphor screen are simulated, displaying various patterns characteristic of each adsorption configuration.open546

    A Measurement of Psi(2S) Resonance Parameters

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    Cross sections for e+e- to hadons, pi+pi- J/Psi, and mu+mu- have been measured in the vicinity of the Psi(2S) resonance using the BESII detector operated at the BEPC. The Psi(2S) total width; partial widths to hadrons, pi+pi- J/Psi, muons; and corresponding branching fractions have been determined to be Gamma(total)= (264+-27) keV; Gamma(hadron)= (258+-26) keV, Gamma(mu)= (2.44+-0.21) keV, and Gamma(pi+pi- J/Psi)= (85+-8.7) keV; and Br(hadron)= (97.79+-0.15)%, Br(pi+pi- J/Psi)= (32+-1.4)%, Br(mu)= (0.93+-0.08)%, respectively.Comment: 8 pages, 6 figure

    Measurements of the Mass and Full-Width of the ηc\eta_c Meson

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    In a sample of 58 million J/ψJ/\psi events collected with the BES II detector, the process J/Ïˆâ†’ÎłÎ·c\psi\to\gamma\eta_c is observed in five different decay channels: ÎłK+K−π+π−\gamma K^+K^-\pi^+\pi^-, ÎłÏ€+π−π+π−\gamma\pi^+\pi^-\pi^+\pi^-, ÎłK±KS0π∓\gamma K^\pm K^0_S \pi^\mp (with KS0→π+π−K^0_S\to\pi^+\pi^-), ÎłÏ•Ï•\gamma \phi\phi (with ϕ→K+K−\phi\to K^+K^-) and Îłppˉ\gamma p\bar{p}. From a combined fit of all five channels, we determine the mass and full-width of ηc\eta_c to be mηc=2977.5±1.0(stat.)±1.2(syst.)m_{\eta_c}=2977.5\pm1.0 ({stat.})\pm1.2 ({syst.}) MeV/c2c^2 and Γηc=17.0±3.7(stat.)±7.4(syst.)\Gamma_{\eta_c} = 17.0\pm3.7 ({stat.})\pm7.4 ({syst.}) MeV/c2c^2.Comment: 9 pages, 2 figures and 4 table. Submitted to Phys. Lett.

    Isolated tau leptons in events with large missing transverse momentum at HERA

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    A search for events containing isolated tau leptons and large missing transverse momentum, not originating from the tau decay, has been performed with the ZEUS detector at the electron-proton collider HERA, using 130 pb^-1 of integrated luminosity. A search was made for isolated tracks coming from hadronic tau decays. Observables based on the internal jet structure were exploited to discriminate between tau decays and quark- or gluon-induced jets. Three tau candidates were found, while 0.40 +0.12 -0.13 were expected from Standard Model processes, such as charged current deep inelastic scattering and single W-boson production. To search for heavy-particle decays, a more restrictive selection was applied to isolate tau leptons produced together with a hadronic final state with high transverse momentum. Two candidate events survive, while 0.20 +-0.05 events are expected from Standard Model processes.Comment: 28 pages, 4 figures, 3 tables, accepted by Phys. Lett. B. Updated with minor changes to the text requested by the journal refere
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