Infectious disease control and its economic gains in a pandemic: the case of South Korea

We investigate the role of the infectious disease control (IDC) system in curbing the spread of infectious disease and preventing economic damage during the COVID-19 pandemic. To this end, we propose incorporating a clustering analysis into the synthetic control method. This contributes to constructing a homogeneous donor pool, which is necessary for an unbiased treatment effect estimator. South Korea’s effective IDC system, the so-called K-Quarantine, is estimated to have reduced the number of disease infections and to have prevented a 3.6% loss of GDP and a 0.3%p rise in the unemployment rate in South Korea in 2020. These results are robust in an alternative reduced-form regression analysis under various specifications

Increasing model vertical resolution may not necessarily lead to improved atmospheric predictability

The widely accepted existence of an inherent limit of atmospheric predictability is usually attributed to weather's sensitive dependence on initial conditions. This signature feature of chaos was first discovered in the Lorenz system, initially derived as a simplified model of thermal convection. In a recent study of a high-dimensional generalization of the Lorenz system, it was reported that the predictability of its chaotic solutions exhibits a non-monotonic dimensional dependence. Since raising the dimension of the Lorenz system is analogous to refining the model vertical resolution when viewed as a thermal convection model, it is questioned whether this non-monotonicity is also found in numerical weather prediction models. Predictability in the sense of sensitive dependence on initial conditions can be measured based on deviation time, that is, the time of threshold-exceeding deviations between the solutions with minute differences in initial conditions. Through ensemble experiments involving both the high-dimensional generalizations of the Lorenz system and real-case simulations by a numerical weather prediction model, this study demonstrates that predictability can depend non-monotonically on model vertical resolution. Further analysis shows that the spatial distribution of deviation time strongly contributes to this non-monotonicity. It is suggested that chaos, or sensitive dependence on initial conditions, leads to non-monotonic dependence on model vertical resolution of deviation time and, by extension, atmospheric predictability. Published under an exclusive license by AIP Publishing.N

Exploring crystal phase and morphology in the TiO 2 supporting materials used for visible-light driven plasmonic photocatalyst

The effects of crystal phase and morphology in TiO2 on photocatalytic performance under visible light were experimentally and theoretically investigated. Results reveal that a rutile crystal phase with a three dimensional (3D) morphology was the most favorable supporting material for visible light driven photocatalyst among Au/TiO(2)s. The prolonged localized surface plasmon resonance (LSPR) lifetime and plasmonic coupling of Au induced by the 3D morphology of TiO2 played a key role in enhancing photocatalytic activity. In addition, hot electrons generated on Au by LSPR are preferentially transferred to rutile TiO2 due to the overlapping of density of states (DOS) of Au in the conduction band of rutile TiO2 but obstruction of the reverse directional transfer of electrons to Au by large band bending. Our results provide a strategy for designing suitable plasmonic photocatalysts based on the crystal phase and morphology of TiO2 for solar light-driven photocatalysis applications. (C) 2016 Elsevier B.V. All rights reserved. The effects of crystal phase and morphology in TiO2 on photocatalytic performance under visible light were experimentally and theoretically investigated. Results reveal that a rutile crystal phase with a three dimensional (3D) morphology was the most favorable supporting material for visible light driven photocatalyst among Au/TiO(2)s. The prolonged localized surface plasmon resonance (LSPR) lifetime and plasmonic coupling of Au induced by the 3D morphology of TiO2 played a key role in enhancing photocatalytic activity. In addition, hot electrons generated on Au by LSPR are preferentially transferred to rutile TiO2 due to the overlapping of density of states (DOS) of Au in the conduction band of rutile TiO2 but obstruction of the reverse directional transfer of electrons to Au by large band bending. Our results provide a strategy for designing suitable plasmonic photocatalysts based on the crystal phase and morphology of TiO2 for solar light-driven photocatalysis applications. (C) 2016 Elsevier B.V. All rights reserved.11Nsciescopu

Area-Efficient One-Cycle Correction Scheme for Timing Errors in Flip-Flop Based Pipelines

We propose a new timing error correction scheme for area-efficient design of flip-flop based pipeline. Key features in the proposed scheme are 1) one-cycle error correction using a new local stalling scheme and 2) selective replacement of the error detection and correction flip-flops in critical paths only. A 32-bit MIPS testchip in a 65 nm CMOS technology has been implemented as a testbed. By employing the proposed scheme in the flop-flop based pipeline, the area overhead due to the retiming process (~21%) in the previous two-phase transparent latch based scheme can be eliminated. In addition, substantial area saving (16%) can be achieved compared to the state-of-the-art flip-flop based scheme thanks to the selective replacement of the error detection and correction flip-flops.1