Yejin Kim

Black phosphorus (BP) is an elemental layered material with a strong in-plane anisotropic structure. This structure is accompanied by anisotropic optical, electrical, thermal, and mechanical properties. Despite interest in BP from both fundamental and technical aspects, investigation into the structural dynamics of BP caused by strain fields, which are prevalent for two-dimensional (2D) materials and tune the material physical properties, has been overlooked. Here, we report the morphological dy

Using an energy filter in transmission electron microscopy has enabled elemental mapping at the atomic scale and improved the precision of structural determination by gating inelastic and elastic imaging electrons, respectively. Here, we use an energy filter in ultrafast electron microscopy to enhance the temporal resolution toward the domain of atomic motion. Visualizing transient structures with femtosecond temporal precision was achieved by selecting imaging electrons in a narrow energy distr

Implementing the modern technologies of light-emitting devices, light harvesting, and quantum information processing requires the understanding of the structure-function relations at spatial scales below the optical diffraction limit and time scales of energy and information flows. Here, we distinctively combine cathodoluminescence (CL) with ultrafast electron microscopy (UEM), termed CL-UEM, because CL and UEM synergetically afford the required spectral and spatiotemporal sensitivities, respect

Electron energy-loss spectroscopy (EELS) can measure similar information to x-ray, UV-Vis, and IR spectroscopies but with atomic resolution and increased scattering cross-sections. Recent advances in electron monochromators have expanded EELS capabilities from chemical identification to the realms of synchrotron-level core-loss measurements and to low-loss, 10-100 meV excitations, such as phonons, excitons, and valence structures. EELS measurements are easily correlated with electron diffraction

Polarons are prevalent in condensed matter systems with strong electron-phonon coupling. The adiabaticity of the polaron relates to its transport properties and spatial extent. To date, only adiabatic small polaron formation has been measured following photoexcitation. The lattice reorganization energy is large enough that the first electron–optical phonon scattering event creates a small polaron without requiring substantial carrier thermalization. We measure that frustrating the iron-centered

As viscous hydroxylic organic compounds, diols are of interest for their functional molecular conformation, which is based on inter- and intramolecular hydrogen (H)-bonds. By utilising steady-state electronic and vibrational spectroscopy, time-resolved fluorescence spectroscopy, and computational analyses, we report the association of the hydroxyl groups of diols via intra- or intermolecular H-bonds to enhance their reactivity as a base. Whereas the formation of an intermolecularly H-bonded dime

complex, which was evidenced by the observation that the overall proton-transfer rate constant decreases when a longer-chain diol was used as the bridging wire part. The kinetic isotope effect on the proton relay was investigated to confirm that the nature of the activation barrier for the proton diffusion along the wire is isotope-sensitive proton tunnelling, while for the non-cyclic configuration, the isotope-insensitive H-bond bridge formation is a prerequisite for ESPT.

High Resolution Image Download MS PowerPoint Slide The shaping of matter into desired nanometric structures with on-demand functionalities can enhance the miniaturization of devices in nanotechnology. Herein, strong light–matter interaction was used as an optical lithographic tool to tailor two-dimensional (2D) matter into nanoscale architectures. We transformed 2D black phosphorus (BP) into ultrafine, well-defined, beyond-diffraction-limit nanostructures of ten times smaller size and a hundred

Ultrafast electron microscopy (UEM) has a broad scope of application across material systems and scientific disciplines. In UEM, we investigate multiscale dynamics in the spatial domain ranging from micrometres to ångströms, in reciprocal space, and on timescales from microseconds to attoseconds, with an energy resolution of a few electronvolts or less. Notably, UEM has played a pivotal role in visualisation of ultrafast structural dynamics with high local selectivity, enabling the exploration o

인간의 편견에 대한 불신과 이를 극복할 대안으로 급부상한 인공지능의 빠른 발전에 더하여 전 세계적인 코로나19의 확산과 비대면 면접의 확대는 인공지능의 노동 세계의 침투를 더욱 가속화 하였다. 그러나 아마존의 인공지능 채용툴의 여성 차별적 사례 등을 통해 인공지능에 의한 판단이 오히려 차별을 확산시킬 우려가 확대되었고, 이에 대해 미국은 일리노이주의 “인공지능 영상면접법”이나 뉴욕시의 “자동화된 채용 결정 도구에 관한 법”, 미국 고용평등기회위원회(EEOC)의 장애인 차별 금지 가이드라인 등을 통해 채용 절차상 인공지능에 의한 의사결정이 가져다 줄 수 있는 차별적인 문제점을 최소화 하기 위한 방안을 적극적으로 고민해왔다. 한국의 경우 「채용절차의 공정화에 관한 법률」의 개정을 통하여 인공지능을 통한 채용 절차에 있어 공정성을 확보하고자 하나 현재 제안된 법안은 인공지능 채용에 대한 명확한 정의가 내려져 있지 않으며, 위반 시 제재대상 및 그 정도에 대한 고려가 부족하다. 단순한 관련

L-ascorbic acid (vitamin C) is one of the well-known antiviral agents, especially to influenza virus. Since the in vivo antiviral effect is still controversial, we investigated whether vitamin C could regulate influenza virus infection in vivo by using Gluo (-/-) mice, which cannot synthesize vitamin C like humans. First, we found that vitamin C-insufficient Gluo (-/-)mice expired within 1 week after intranasal inoculation of influenza virus (H3N2/Hongkong). Viral titers in the lung of vitamin C

With the advancement of artificial intelligence technology and the progression of digital transformation, algorithmic management is expanding beyond digital labor platforms into traditional work environments. This study examines the adequacy of algorithmic management regulation through a comparative analysis of the EU AI Act and Platform Work Directive, focusing on transparency and participation requirements. The research finds that while the AI Act presents comprehensive transparency requiremen

Purpose: In Korea, since the Act on Hospice and Palliative Care and Decisions on Life- Sustaining Treatment for Patients at the End of Life was implemented in February 2018, advance directives (ADs) have become legally effective and should be documented after sufficient explanation by a registered counselor. However, little is known regarding the adequacy of current AD counseling. This qualitative study aimed to explore the barriers to AD counseling based on counselors’ experiences. Methods: We

In the era of coronavirus disease 2019 (COVID-19), social distancing and strict visitation policies at hospitals have made it difficult for medical staff to provide high-quality endof- life (EOL) care to dying patients and their families. There are various issues related to EOL care, including psychological problems of patients and their families, difficulties in EOL decision-making, the complicated grief of the bereaved family, moral distress, and exhaustion of medical staff. In relation to the