Donghyun Lee

Abstract. In the last decade, the Climate Limited-area Modeling Community (CLM-Community) has contributed to the Coordinated Regional Climate Downscaling Experiment (CORDEX) with an extensive set of regional climate simulations. Using several versions of the COSMO-CLM-Community model, ERA-Interim reanalysis and eight global climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5) were dynamically downscaled with horizontal grid spacings of 0.44∘ (∼ 50 km), 0.22∘ (∼ 25 km)

An enzyme-metal combo reaction has been developed for the dynamic kinetic resolution of allylic alcohols in which racemic substrates are transformed by a lipase and a ruthenium complex in the presence of an acyl donor to allylic acetates of high optical purity in over 80% yield.

We demonstrated AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs) with periodic air-voids-incorporated nanoscale patterns enabled by nanosphere lithography and epitaxial lateral overgrowth (ELO) on a 4-in. sapphire substrate. The nanoscale ELO improved the crystal quality of overgrown epitaxial layers at a relatively low growth temperature of 1050 °C and at small coalescence thickness less than 2 μm. The light output power of the DUV LED was enhanced significantly by 67% at an inject

Abstract The diagnosis of liver diseases is generally carried out via ultrasound imaging, computed tomography, and magnetic resonance imaging. The emerging photoacoustic imaging is an attractive alternative to diagnose even early stage of liver diseases providing high‐resolution anatomical and functional information in deep tissue noninvasively. However, the liver has insufficient photoacoustic contrast due to low optical absorbance in the near‐infrared windows. Here, a new hyaluronate–silica na

This study investigates the impacts of global warming of 1.5 °C and 2.0 °C above pre-industrial conditions (Paris Agreement target temperatures) on the South Asian and East Asian monsoon rainfall using five atmospheric global climate models participating in the 'Half a degree Additional warming, Prognosis and Projected Impacts' (HAPPI) project. Mean and extreme precipitation is projected to increase under warming over the two monsoon regions, more strongly in the 2.0 °C warmer world. Moisture bu

Since its first implementation in otolaryngological surgery nearly a century ago, the surgical microscope has improved the accuracy and the safety of microsurgeries. However, the microscope shows only a magnified surface view of the surgical region. To overcome this limitation, either optical coherence tomography (OCT) or photoacoustic microscopy (PAM) has been independently combined with conventional surgical microscope. Herein, we present a near-infrared virtual intraoperative photoacoustic op

Mobile chargers (MCs) equipped with radio-frequency (RF)-based wireless power transfer (WPT) modules have been suggested as a possible solution to battery constraints in wireless rechargeable sensor networks (WRSNs). In RF-based WPT, charging efficiency decreases significantly as the charging distance increases. Therefore, single charging consumes less energy than multicharging because it can generally charge a sensor node at a closer range. However, when the density of nodes is high, multicharg

X-ray acoustic imaging is a hybrid biomedical imaging technique that can acoustically monitor X-ray absorption distribution in biological tissues through the X-ray induced acoustic effect. In this study, we developed a 3D volumetric X-ray-induced acoustic computed tomography (XACT) system with a portable pulsed X-ray source and an arc-shaped ultrasound array transducer. 3D volumetric XACT images are reconstructed via the back-projection algorithm, accelerated by a custom-developed graphics proce

This paper presents experimental results of self-interference cancellation of a full-duplex radio front-end. The proposed RF front-end uses three antennas for a 1-TX and 2 (primary and diversity)-RX MISO system without RF circulators. Transmitting signals are fed to two identical antennas through a rat race coupler with 180° phase difference, resulting in the signal cancellation at the RX diversity antenna which is equally spaced from transmitting antennas. Using the isolation port of the rat ra

The substrate matching strategy is described as a new approach for effectively enhancing the lipase enantioselectivity in organic solvent. In the lipase-catalyzed transesterifications of 3a-c, higher enantioselectivities have been achieved using 1a-c, respectively, as the structurally matched acyl donors.

We consider viscous free-boundary magnetohydrodynamics (MHD) under vacuum in $\mathbb{R}^3$, especially when the vacuum magnetic field is identically zero. It is a central problem in mathematics to perform the vanishing viscosity limit to get a solution of a hyperbolic inviscid system. However, boundary layer behavior happens near the free boundary, so the existence time $T^{\varepsilon} \rightarrow 0$ as the kinematic viscosity $\varepsilon\rightarrow 0$ in standard Sobolev space. Inspired by [

Currently, x-ray-based imaging is used before and after the dental implant treatment, but the ionizing radiation is potentially harmful to patients and operators. Here, we demonstrate ex vivo photoacoustic imaging of a dental implant embedded in a porcine jawbone. By layering biological tissue over the jawbone to mimic a clinical environment, we demonstrate 10 mm deep imaging. Our results show that photoacoustic imaging can provide jawbone anatomical information, the location of an embedded impl