Agenda setting and micro-blog use: An analysis of the relationship between Sina Weibo and newspaper agendas in China

The present study investigates the influence of micro-blogs on the major agenda-setting media in China in the immediate aftermath of a catastrophic railway accident. Study findings are based on a content analysis of micro-blog messages and traditional mainstream media reports that were published in the nine days subsequent to the July 23, 2011 bullet train crash accident. Results suggest that, in the immediate aftermath of a catastrophic train wreck, alternative online media played a decisive role in setting mainstream media agendas and providing a citizen forum on a sensitive issue that their conventional counterparts downplayed, ignored, or missed altogether. In particular, the traditional media’s agenda setting power is no longer universal nor singular within micro-blogging outlets. Instead, traditional media—once a monolithic establishment—are now just one of the role players among many competing influences

An online position error correction method for sensorless control of permanent magnet synchronous machine with parameter mismatch

To eliminate the influence of parameter mismatch for fundamental model based sensorless methods, an effective online position error correction method is proposed for permanent magnet synchronous machines in this paper. Based on the derived position error mechanism, i.e. the error varies proportionally to the dq -axis currents, the proposed method injects a sinusoidal current signal with a small amplitude and low frequency into the d - or q -axis current for a short period. During injection, the corresponding sinusoidal response for current injection can be acquired from the estimated speed of the sensorless position observer. It is found that the amplitude of the response in the estimated speed decreases as the parameter mismatch reduces, and eventually reaches a minimum if there is no parameter mismatch. Thus, by applying the least mean square (LMS) algorithm, the amplitude of the response in the estimated speed can be minimised as the parameters are adaptively adjusted to the actual values, and then the position error can be corrected. The proposed method is validated through experiments on a permanent magnet generator drive system

Characterization of the monoclonal antibody against classical swine fever virus glycoprotein E-rns and its application to an indirect sandwich ELISA

Classical swine fever virus (CSFV) E-rns is an envelope glycoprotein possessing RNase activity. The E-rns-based enzyme-linked immunosorbent assay (ELISA) has been considered a discriminating diagnostic test for differentiating infected from vaccinated animals. The purpose of this study was to produce a specific monoclonal antibody (MAb) to E-rns for further developing an indirect sandwich ELISA. The MAb CW813 was shown to specifically recognize both the monomer and dimer forms of Pichia pastoris yeast-expressed E-rns (yE(rns)). The antigenic site recognized by MAb CW813 was mapped to the region of amino acid residues 101-160 of E-rns where it was neither a neutralizing epitope nor essential to RNase activity. Furthermore, MAb CW813 was utilized as a capture antibody to develop a yE(rns)-based indirect sandwich ELISA for detecting swine antibody to E-rns. The assay demonstrated a high sensitivity and specificity that may provide an alternative method for developing a diagnostic kit with easy manipulation and low cost

Modeling water waves beyond perturbations

In this chapter, we illustrate the advantage of variational principles for modeling water waves from an elementary practical viewpoint. The method is based on a `relaxed' variational principle, i.e., on a Lagrangian involving as many variables as possible, and imposing some suitable subordinate constraints. This approach allows the construction of approximations without necessarily relying on a small parameter. This is illustrated via simple examples, namely the Serre equations in shallow water, a generalization of the Klein-Gordon equation in deep water and how to unify these equations in arbitrary depth. The chapter ends with a discussion and caution on how this approach should be used in practice.Comment: 15 pages, 1 figure, 39 references. This document is a contributed chapter to an upcoming volume to be published by Springer in Lecture Notes in Physics Series. Other author's papers can be downloaded at http://www.denys-dutykh.com

Approximate k-state solutions to the Dirac-Yukawa problem based on the spin and pseudospin symmetry

Using an approximation scheme to deal with the centrifugal (pseudo-centrifugal) term, we solve the Dirac equation with the screened Coulomb (Yukawa) potential for any arbitrary spin-orbit quantum number {\kappa}. Based on the spin and pseudospin symmetry, analytic bound state energy spectrum formulas and their corresponding upper- and lower-spinor components of two Dirac particles are obtained using a shortcut of the Nikiforov-Uvarov method. We find a wide range of permissible values for the spin symmetry constant C_{s} from the valence energy spectrum of particle and also for pseudospin symmetry constant C_{ps} from the hole energy spectrum of antiparticle. Further, we show that the present potential interaction becomes less (more) attractive for a long (short) range screening parameter {\alpha}. To remove the degeneracies in energy levels we consider the spin and pseudospin solution of Dirac equation for Yukawa potential plus a centrifugal-like term. A few special cases such as the exact spin (pseudospin) symmetry Dirac-Yukawa, the Yukawa plus centrifugal-like potentials, the limit when {\alpha} becomes zero (Coulomb potential field) and the non-relativistic limit of our solution are studied. The nonrelativistic solutions are compared with those obtained by other methods.Comment: 21 pages, 6 figure