Comment on Counterintuitive consequence of heating in strongly driven intrinsic junctions of Bi2_2Sr2_2CaCu2_2O8+δ_{8+\delta} mesas

In a recent paper [Phys.Rev.B 81, 224518 (2010)], C. Kurter et al, analyzed the effect of strong self-heating in large-area Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ (Bi-2212) mesa structures. They conclude that $dI/dV$ conductance peaks in their mesas occur when mesas are heated to the superconducting critical temperature $T_c$. Further on they extrapolate this statement for all mesas, including much smaller and much better thermally anchored mesas used in Intrinsic Tunnelling Spectroscopy (ITS). Here I show that their conclusion does not hold neither for previously reported data, nor even for their own mesas; the very remote extrapolation to ITS is invalid. I also point out a number of inconsistencies and misleading references.Comment: 2 page

Degradation of multiplier phototubes exposed to spatial radiations

Degradation of multiplier phototubes exposed to spatial radiation

Information Technology Externalities: Empirical Evidence from 42 U.S. Industries

Using interindustry transaction in input-output tables, we examine Information Technology (IT) externalities in U.S. private industries over the period 1984-2000. Our empirical results show that computerization of an industry's customer and supplier industries reduces both labor and material costs of the industry. Moreover, cost savings driven by supplier industries are larger than those driven by customer industries. We also find that industries in the services sector enjoy more benefits from IT spillovers than industries in other sectors because of their high IT capital intensity and composition of interindustry transaction. Decomposition of total factor productivity (TFP) suggests that IT externalities can explain considerable parts of TFP growth, although possible mismeasurement of output in services industries leads to exacerbated technical changes of services industries.

Stability of Transonic Characteristic Discontinuities in Two-Dimensional Steady Compressible Euler Flows

For a two-dimensional steady supersonic Euler flow past a convex cornered wall with right angle, a characteristic discontinuity (vortex sheet and/or entropy wave) is generated, which separates the supersonic flow from the gas at rest (hence subsonic). We proved that such a transonic characteristic discontinuity is structurally stable under small perturbations of the upstream supersonic flow in $BV$. The existence of a weak entropy solution and Lipschitz continuous free boundary (i.e. characteristic discontinuity) is established. To achieve this, the problem is formulated as a free boundary problem for a nonstrictly hyperbolic system of conservation laws; and the free boundary problem is then solved by analyzing nonlinear wave interactions and employing the front tracking method.Comment: 26 pages, 3 figure

Do Local Analysts Know More? A Cross-Country Study of the Performance of Local Analysts and Foreign Analysts

This paper examines whether analysts resident in a country make more precise earnings forecasts for firms in that country than analysts who are not resident in that country. Using a sample of 32 countries, we find that there is an economically and statistically significant analyst local advantage even after controlling for firm and analyst characteristics. The importance of the local advantage is inversely related to the quality of the information provided by firms. In particular, the local advantage is high in countries where earnings are smoothed more, less information is disclosed by firms, and firm idiosyncratic information explains a smaller fraction of stock returns. The local advantage is also negatively related to market participation by foreign investors and by institutions and positively related to holdings by insiders. U.S. investors underweight a country's stocks more in their portfolios if that country has a higher analyst local advantage.

The effects of pausing on comprehensibility

Pausing effects how well listeners understand and attend to meaning in discourse. This study investigates the effects of three different pause treatments (irregular placement, increased frequency, and longer length) on comprehensibility ratings. Varonis and Gass (1982) found that a complex interaction of factors affected comprehensibility ratings. These included pronunciation, grammar, familiarity and fluency. While many of these features have been investigated (Anderson-Hsieh, Johnson, & Koehler, 1992; Derwing & Munro, 1997; Hahn, 2004; Isaacs & Trofimovich, 2012; Kang, 2010; Munro & Derwing, 1995), pausing has received little attention. In this study, an extended NNS speech sample with native-like pausing was manipulated, creating three experimental recordings, one with irregularly placed pauses, one with increased pause frequency, and one with longer pauses. Forty-three undergraduates in four different class groups listened to each of the pause treatments and rated them for comprehensibility. In addition to comprehensibility measures, participants also rated each treatment for fluency based on Griffiths\u27 (1991) proposition that pausing is often tied to fluency. This allowed for a comparison of the effects of pausing on comprehensibility to those on fluency. Additionally, this study investigated the strength of Kang\u27s (2010) revised comprehensibility instrument. The results showed that irregular pause placement was the greatest detriment to comprehensibility, followed by pause frequency. These results may be explained by the psycholinguistic model of language processing which assumes we process language in chunks. When NNSs pause irregularly, NS listeners must process each word individually to make meaning instead of processing the chunk through expected phrasing. This, in turn, causes lower comprehensibility ratings. These results advocate for the teaching of formulaic language in the ESL/EFL classroom so that attention to pause placement in conjunction with work on fluency facilitates more comprehensible speech

125 GeV Higgs as a pseudo-Goldstone boson in supersymmetry with vector-like matters

We propose a possibility of the 125 GeV Higgs being a pseudo-Goldstone boson in supersymmetry with extra vector-like fermions. Higgs mass is obtained from loops of top quark and vector-like fermions from the global symmetry breaking scale f at around TeV. The mu, Bmu/mu \sim f are generated from the dynamics of global symmetry breaking and the Higgs quartic coupling vanishes at f as tan beta \simeq 1. The relation of msoft \sim $4\pi M_Z$ with f \sim mu \sim m_soft \sim TeV is obtained and large mu does not cause a fine tuning for the electroweak symmetry breaking. The Higgs to di-photon rate can be enhanced from the loop of uncolored vector-like matters. The stability problem of Higgs potential with vector-like fermions can be nicely cured by the UV completion with the Goldstone picture.Comment: 28 pages, 8 figure