Youngmin Kim

Semiempirical interatomic potentials for hcp elements, Ti and Zr, have been developed based on the MEAM (modified embedded-atom method) formalism. The new potentials do not cause the stability problem previously reported in MEAM for hcp elements, and describe wide range of physical properties (bulk properties, point defect properties, planar defect properties, and thermal properties) of pure Ti and Zr, in good agreement with experimental information. The applicability of the potentials to atomis

Continuous advancement in nonvolatile and morphotropic beyond-Moore electronic devices requires integration of ferroelectric and semiconductor materials. The emergence of hafnium oxide (HfO 2 )–based ferroelectrics that are compatible with atomic-layer deposition has opened interesting and promising avenues of research. However, the origins of ferroelectricity and pathways to controlling it in HfO 2 are still mysterious. We demonstrate that local helium (He) implantation can activate ferroelectr

Multi-view stereo methods frequently fail to properly reconstruct 3D scene geometry if visible texture is sparse or the scene exhibits difficult self-occlusions. Time-of-Flight (ToF) depth sensors can provide 3D information regardless of texture but with only limited resolution and accuracy. To find an optimal reconstruction, we propose an integrated multi-view sensor fusion approach that combines information from multiple color cameras and multiple ToF depth sensors. First, multi-view ToF senso

We performed multiple drilling as a femoral head-preserving procedure for osteonecrosis of the femoral head thinking the therapeutic effects of core decompression could be achieved by this simpler procedure than core decompression. We retrospectively reviewed 136 patients (163 hips) who had multiple drilling using 9/64-inch Steinmann pins for treatment of nontraumatic osteonecrosis of the femoral head. The mean followup for patients who did not require additional surgery (113 hips) was 87 months

Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is activated during ATP-depleting metabolic states, such as hypoxia, heat shock, oxidative stress, and exercise. As a highly conserved heterotrimeric kinase that functions as a major metabolic switch to maintain energy homeostasis, AMPK has been shown to exert as an intrinsic regulator of mammalian cell cycle. Moreover, AMPK cascade has emerged as an important pathway implicated in cancer control. In this article, we have investigated

Chemical treatment using bis(trifluoromethane) sulfonimide (TFSI) was shown to be particularly effective for increasing the photoluminescence (PL) of monolayer (1L) MoS₂, suggesting a convenient method for overcoming the intrinsically low quantum yield of this material. However, the underlying atomic mechanism of the PL enhancement has remained elusive. Here, we report the microscopic origin of the defect healing observed in TFSI-treated 1L-MoS₂ through a correlative combin

Heterointerface stabilization of a distinct nonpolar BiFeO3 phase occurs simultaneously with changes in octahedral tilts. The resulting phase arises via suppression of polarization by a structural order parameter and can thus be identified as anti-ferroelectric (Fe displacements - bottom panel). The phase is metastable and can be switched into a polar ferroelectric state (top panel) under an applied electric bias.

The effects of Al 3+ , B 3+ , P 5+ , Fe 3+ , S 6+ , and K + ions on the stability of the β‐phase and its hydration rate were studied in reactive dicalcium silicate (C 2 S, Ca 2 SiO 4 ) synthesized using the Pechini process. In particular, the dependences of the phase stability and degree of hydration on the calcination temperature (i.e., particle size) and the concentration of the stabilizing ions were investigated. The phase evolution in doped C 2 S was determined using XRD, and the degree of h

The interface-type resistive switching devices exhibiting bipolar and multi-level resistive switching have been considered as the key component for neuromorphic device applications. To directly observe the microscopic details of underlying electrochemical redox reactions occuring at a metal/oxide interface, we implemented in situ resistive switching of TiN/Pr_0.7Ca_0.3MnO₃ (PCMO)/Pt junction devices in a transmission electron microscope (TEM). The in situ TEM obser

Exposure to meteorological variables and air pollutants are associated with AD symptoms in young children.