The invisible model minority : images of Koreans on American TV

There is a growing literature on how television employs stereotypes especially about ethnic minorities. But these studies investigating audience impact of negative images on TV have relatively excluded Korean-Americans, one of the largest Asian-American ethnic minority groups. To answer this need and to further examine the axioms of cultivation theory, this study assessed how American students in a Midwestern land grant university perceive images of Korean-Americans on TV. A stratified cluster sampling of students attending 1997 summer classes at Iowa State University was surveyed. Results did not lend support to the cultivation hypothesis: subjects simply did not ascribe stereotypical television portrayals of Korean-American characters to their perceptions of real-life Korean-Americans. Respondents\u27 perceptions were also not affected by the amount of time they spent watching television, face-to-face contact or interpersonal relationship with a real Korean-American, nor by their area of residence (whether urban or rural)

Yet Another Tutorial of Disturbance Observer: Robust Stabilization and Recovery of Nominal Performance

This paper presents a tutorial-style review on the recent results about the disturbance observer (DOB) in view of robust stabilization and recovery of the nominal performance. The analysis is based on the case when the bandwidth of Q-filter is large, and it is explained in a pedagogical manner that, even in the presence of plant uncertainties and disturbances, the behavior of real uncertain plant can be made almost similar to that of disturbance-free nominal system both in the transient and in the steady-state. The conventional DOB is interpreted in a new perspective, and its restrictions and extensions are discussed

Electron-hole asymmetry in Co- and Mn-doped SrFe2As2

Phase diagram of electron and hole-doped SrFe2As2 single crystals is investigated using Co and Mn substitution at the Fe-sites. We found that the spin-density-wave state is suppressed by both dopants, but the superconducting phase appears only for Co (electron)-doping, not for Mn (hole)-doping. Absence of the superconductivity by Mn-doping is in sharp contrast to the hole-doped system with K-substitution at the Sr sites. Distinct structural change, in particular the increase of the Fe-As distance by Mn-doping is important to have a magnetic and semiconducting ground state as confirmed by first principles calculations. The absence of electron-hole symmetry in the Fe-site-doped SrFe2As2 suggests that the occurrence of high-Tc superconductivity is sensitive to the structural modification rather than the charge doping.Comment: 7 pages, 6 figure

Remarkable charge-transfer mobility from [6] to [10]phenacene as a high performance p-type organic semiconductor

The relationship between structure and charge transport properties of phenacene organic semiconductors has been studied with focus on [6] -> [10] phenacene. Upon inserting phenyl rings, the p-extended structure results in strong electronic coupling interactions and reduction of reorganization energy. Using the classical Marcus charge transport theory, we predict that hole mobility in the phenacene series increases gradually up to 8.0 cm(2) V-1 s(-1) at [10] phenacene. This is remarkably high among other discovered OSCs, surpassing that of pentacene. Moreover, we notice that the experimental hole mobility of [6] phenacene is unusually low, inconsistent with other members in the same series. Thus, we performed full structural relaxation on phenacene and revealed similarities between theoretical and experimental crystal structures for all the members except [6] phenacene. We propose a new structure of [6] phenacene under the consideration of van der Waals force with smaller lattice parameters a* and b* compared to the experimental structure. Our new structural calculation fits well with the existing trend of hole mobility, energy gaps, effective masses, bandwidth and lattice parameters. Single-shot G(0)W(0) calculations are performed to verify our structures. The results give a hint that the improvement in [6] phenacene efficiency lies on the intermolecular distance along the stacking direction of the crystal. Phenacene compounds generally have small effective masses, high charge transfer integrals and moderate reorganization energies necessary for hole transport. Our results suggest that the phenacene series, in particular [6] -> [10]phenacene, have high charge mobility and air stability essential for achieving high efficiency electronic devices.11Ysciescopu