15,257 research outputs found

    The export competitiveness of the newly industrialised east Asian economies: How real is the Chinese threat in electronics?

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    This paper examines the export performance of China in electronics compared to the east Asian NIEs exporting to the USA, the European Union, and Japan between 1988 and 2001 using a dynamic version of shift-share analysis to overcome some of the inherent drawbacks of the widely-used static shift-share methodology. Our findings suggest that China has now emerged as a serious contender in the export market for electronic goods, but this position has not been a dominant one. For electronics as a whole, the principal gainers after 1995 appear to be newcomers China and Malaysia at the expense of the older Tigers, like Singapore and Hong Kong. To some extent this represents a natural process of ‘catch-up’. Moreover, no single NIE has dominated all categories of electronic exports. In the east Asian region, the less developed members of ASEAN would appear to be most at risk in the immediate future since they compete head on with China in lower-end manufacturing and are in danger of being ‘leapfrogged’ in the value-added chain. The more advanced NIEs are in a better position since they have time to increase value-added before China catches up and may benefit more from the opportunities China offers in terms of production and service complementarities

    A challenge to the permissibility of procreation

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    The Non-Identity Problem (the NIP) raises a series of problems to the morality of procreation. The NIP, I believe, highlights a fundamental problem concerning the justifiability of procreation. In chapter 1, I introduce the NIP and show that the logic of the NIP does not rule out the anti-natalist claim. Moreover, there are reasons, which are independent of its capacity to solve the NIP, to accept the anti-natalist claim. However, the anti-natalist claim poses a serious justificatory challenge to the permissibility of procreation. To see whether we can restore the permissibility of procreation, I examine the impersonal pro-natalist claim in chapter 2 and argue that there is not only no good reason to believe that whatever makes life worth living gives us an impersonal reason to procreate but good reason not to believe that. In chapter 3, I examine the justifications for the right to procreate and argue that most promising ground – that is, parenting interest – fails to establish a moral right to procreate. Therefore, the justification of procreation is in trouble, at least, at the individual level because there is a reason against procreation out of concern for possible people and no impersonal reason to procreate and the moral significance of parenting interests fails to justify imposing the harm of coming into existence. This is, nevertheless, a somewhat moderate conclusion because it does not defend that procreation is all-things-considered wrong. More works need to be done to show why procreation is morally permissible (or impermissible)

    On Refining Twitter Lists as Ground Truth Data for Multi-Community User Classification

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    To help scholars and businesses understand and analyse Twitter users, it is useful to have classifiers that can identify the communities that a given user belongs to, e.g. business or politics. Obtaining high quality training data is an important step towards producing an effective multi-community classifier. An efficient approach for creating such ground truth data is to extract users from existing public Twitter lists, where those lists represent different communities, e.g. a list of journalists. However, ground truth datasets obtained using such lists can be noisy, since not all users that belong to a community are good training examples for that community. In this paper, we conduct a thorough failure analysis of a ground truth dataset generated using Twitter lists. We discuss how some categories of users collected from these Twitter public lists could negatively affect the classification performance and therefore should not be used for training. Through experiments with 3 classifiers and 5 communities, we show that removing ambiguous users based on their tweets and profile can indeed result in a 10% increase in F1 performance

    Lensfree on-chip microscopy over a wide field-of-view using pixel super-resolution.

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    We demonstrate lensfree holographic microscopy on a chip to achieve approximately 0.6 microm spatial resolution corresponding to a numerical aperture of approximately 0.5 over a large field-of-view of approximately 24 mm2. By using partially coherent illumination from a large aperture (approximately 50 microm), we acquire lower resolution lensfree in-line holograms of the objects with unit fringe magnification. For each lensfree hologram, the pixel size at the sensor chip limits the spatial resolution of the reconstructed image. To circumvent this limitation, we implement a sub-pixel shifting based super-resolution algorithm to effectively recover much higher resolution digital holograms of the objects, permitting sub-micron spatial resolution to be achieved across the entire sensor chip active area, which is also equivalent to the imaging field-of-view (24 mm2) due to unit magnification. We demonstrate the success of this pixel super-resolution approach by imaging patterned transparent substrates, blood smear samples, as well as Caenoharbditis Elegans

    Spin dynamics in electron-doped pnictide superconductors

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    The doping dependence of spin excitations in Ba(Fe1x_{1-x}Cox_{x})2_{2}As2_{2} is studied based on a two-orbital model under RPA approximation. The interplay between the spin-density-wave (SDW) and superconductivity (SC) is considered in our calculation. Our results for the spin susceptibility are in good agreement with neutron scattering (NS) experiments in various doping ranges at temperatures (T) above and below the superconducting transition temperature Tc_{c}. For the overdoped sample where one of the two hole pockets around Γ\Gamma point disappears according to ARPES, we show that the imaginary part of the spin susceptibility in both SC and normal phases exhibits a gap-like behavior. This feature is consistent with the "pseudogap" as observed by recent NMR and NS experiments.Comment: 5 pages, 2 figure

    Lensless wide-field fluorescent imaging on a chip using compressive decoding of sparse objects.

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    We demonstrate the use of a compressive sampling algorithm for on-chip fluorescent imaging of sparse objects over an ultra-large field-of-view (>8 cm(2)) without the need for any lenses or mechanical scanning. In this lensfree imaging technique, fluorescent samples placed on a chip are excited through a prism interface, where the pump light is filtered out by total internal reflection after exciting the entire sample volume. The emitted fluorescent light from the specimen is collected through an on-chip fiber-optic faceplate and is delivered to a wide field-of-view opto-electronic sensor array for lensless recording of fluorescent spots corresponding to the samples. A compressive sampling based optimization algorithm is then used to rapidly reconstruct the sparse distribution of fluorescent sources to achieve approximately 10 microm spatial resolution over the entire active region of the sensor-array, i.e., over an imaging field-of-view of >8 cm(2). Such a wide-field lensless fluorescent imaging platform could especially be significant for high-throughput imaging cytometry, rare cell analysis, as well as for micro-array research

    Characterizing Intermittency of 4-Hz Quasi-periodic Oscillation in XTE J1550-564 using Hilbert-Huang Transform

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    We present the time-frequency analysis results based on the Hilbert-Huang transform (HHT) for the evolution of a 4-Hz low-frequency quasi-periodic oscillation (LFQPO) around the black hole X-ray binary XTE J1550-564. The origin of LFQPOs is still debated. To understand the cause of the peak broadening, we utilized a recently developed time-frequency analysis, HHT, for tracking the evolution of the 4-Hz LFQPO from XTE J1550 564. By adaptively decomposing the ~4-Hz oscillatory component from the light curve and acquiring its instantaneous frequency, the Hilbert spectrum illustrates that the LFQPO is composed of a series of intermittent oscillations appearing occasionally between 3 Hz and 5 Hz. We further characterized this intermittency by computing the confidence limits of the instantaneous amplitudes of the intermittent oscillations, and constructed both the distributions of the QPO's high and low amplitude durations, which are the time intervals with and without significant ~4-Hz oscillations, respectively. The mean high amplitude duration is 1.45 s and 90% of the oscillation segments have lifetimes below 3.1 s. The mean low amplitude duration is 0.42 s and 90% of these segments are shorter than 0.73 s. In addition, these intermittent oscillations exhibit a correlation between the oscillation's rms amplitude and mean count rate. This correlation could be analogous to the linear rms-flux relation found in the 4-Hz LFQPO through Fourier analysis. We conclude that the LFQPO peak in the power spectrum is broadened owing to intermittent oscillations with varying frequencies, which could be explained by using the Lense-Thirring precession model.Comment: 27 pages, 9 figures, accepted for publication in The Astrophysical Journa
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