Korea University

About: Korea University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Population & Catalysis. The organization has 39756 authors who have published 82424 publications receiving 1860927 citations. The organization is also known as: Bosung College & Bosung Professional College.

Active terahertz nanoantennas based on VO2 phase transition.

Abstract: Unusual performances of metamaterials such as negative index of refraction, memory effect, and cloaking originate from the resonance features of the metallic composite atom1−6. Indeed, control of metamaterial properties by changing dielectric environments of thin films below the metallic resonators has been demonstrated7−11. However, the dynamic control ranges are still limited to less than a factor of 10,7−11 with the applicable bandwidth defined by the sharp resonance features. Here, we present ultra-broad-band metamaterial thin film with colossal dynamic control range, fulfilling present day research demands. Hybridized with thin VO2 (vanadium dioxide)(12-18) films, nanoresonator supercell arrays designed for one decade of spectral width in terahertz frequency region show an unprecedented extinction ratio of over 10000 when the underlying thin film experiences a phase transition. Our nanoresonator approach realizes the full potential of the thin film technology for long wavelength applications.

Does Corporate Social Responsibility Affect Information Asymmetry

Abstract: In this study, we examine the empirical association between corporate social responsibility (CSR) and information asymmetry by investigating their simultaneous and endogenous effects. Employing an extensive U.S. sample, we find an inverse association between CSR engagement and the proxies of information asymmetry after controlling for various firm characteristics. The results hold using 2SLS considering the reverse side of information asymmetry influencing CSR activities. The results also hold after mitigating endogeneity based on the dynamic panel system generalized method of moment. Furthermore, the CSR–information asymmetry relation is amplified in high-risk firms due to managers’ efforts to build a good reputation. Last, we find that CSR engagement is inversely associated with reputational risk measure and lower predicted value of reputational risk is positively associated with lower information asymmetry measures. We interpret these results as supporting the stakeholder theory-based, reputation-building explanation that considers CSR engagement as a vehicle to build and maintain firm reputation thereby enhancing the information environment.

Searches for electroweak production of charginos, neutralinos, and sleptons decaying to leptons and W, Z, and Higgs bosons in pp collisions at 8 TeV

Abstract: Searches for the direct electroweak production of supersymmetric charginos, neutralinos, and sleptons in a variety of signatures with leptons and W, Z, and Higgs bosons are presented. Results are based on a sample of proton-proton collision data collected at center-of-mass energy sqrt(s) = 8 TeV with the CMS detector in 2012, corresponding to an integrated luminosity of 19.5 inverse femtobarns. The observed event rates are in agreement with expectations from the standard model. These results probe charginos and neutralinos with masses up to 720 GeV, and sleptons up to 260 GeV, depending on the model details.