A5100444717- Nonlinear Photonic Systems
- Dark Matter and Cosmic Phenomena
- Education, Safety, and Science Studies
- Educational Research and Pedagogy
- Particle physics theoretical and experimental studies
- Education and Learning Interventions
- Quantum chaos and dynamical systems
- Cosmology and Gravitation Theories
- Cold Atom Physics and Bose-Einstein Condensates
- Analytical Chemistry and Sensors
- Advanced Optical Sensing Technologies
- Scientific Research and Discoveries
- Opinion Dynamics and Social Influence
- Atomic and Subatomic Physics Research
- Nonlinear Dynamics and Pattern Formation
- CCD and CMOS Imaging Sensors
- Experimental and Theoretical Physics Studies
- Quantum optics and atomic interactions
- Mechanical and Optical Resonators
- Complex Network Analysis Techniques
- Advanced Fiber Laser Technologies
- Computational and Text Analysis Methods
- Polydiacetylene-based materials and applications
- Educational Strategies and Epistemologies
- Embedded Systems and FPGA Design
Korea Advanced Institute of Science and Technology
2023-2024
Institute for Basic Science
2023-2024
Cheongju National University of Education
2016-2023
Korea National University of Education
2016-2022
IMEC
2020-2021
Daegu Gyeongbuk Institute of Science and Technology
2015-2019
Sogang University
2015
We report an axion dark matter search at Dine-Fischler-Srednicki-Zhitnitskii sensitivity with the CAPP-12TB haloscope, assuming axions contribute 100% of local density. The excluded axion-photon coupling g_{aγγ} down to about 6.2×10^{-16} GeV^{-1} over mass range between 4.51 and 4.59 μeV a 90% confidence level. achieved experimental can also exclude Kim-Shifman-Vainshtein-Zakharov that makes up just 13% haloscope will continue wide masses.
We report an extensive high-sensitivity search for axion dark matter above 1 GHz at the Center Axion and Precision Physics Research (CAPP). The cavity resonant search, exploiting coupling between axions photons, explored frequency (mass) range of 1.025 (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mn>4.24</a:mn><a:mtext> </a:mtext><a:mtext> </a:mtext><a:mi mathvariant="normal">μ</a:mi><a:mi>eV</a:mi></a:mrow></a:math>) to 1.185 (<d:math...
Fermi resonance is a phenomenon of quantum mechanical superposition, which most often occurs between normal and overtone modes in molecular systems that are nearly coincident energy. We find scarred resonances deformed dielectric microcavities the very resonance, is, pair quasinormal interact with each other due to coupling generated through an avoided crossing. Then number difference modes, consequence equals periodic orbits, whereby localized on orbits. derive relation orbits confirm it...
A large number of different types second-order non-Hermitian degeneracies called exceptional points (EPs) were found in various physical systems depending on the mechanism coupling between eigenstates. We show that these EPs can be hybridized to form higher-order EPs, which preserve original properties initial before hybridization. For a demonstration, we hybridize chiral and supermode where former latter are results intra-disk inter-disk mode an optical system comprised two Mie-scale...
We report an extensive high-sensitivity search for axion dark matter above 1\,GHz at the Center Axion and Precision Physics Research (CAPP). The cavity resonant search, exploiting coupling between axions photons, explored frequency (mass) range of 1.025\,GHz (4.24\,$\mu$eV) to 1.185\,GHz (4.91\,$\mu$eV). have introduced a number innovations in this field, demonstrating practical approach optimizing all relevant parameters haloscopes, extending presently available technology. CAPP 12\,T...
The success of Barack Obama’s 2008 U.S. presidential campaign led politicians and voters all over the world to pay attention social media. Including Donald Trump for his upcoming 2020 re-election, many around have used media their political campaigns. While some can deliver information in various forms (i.e., video, audio, interactive content), popular ones, such as Twitter, are still focused mostly on plain text messaging. With marketing using simple messages via media, there is a need...
Chirality of a resonance localized on an islands chain is studied in deformed Reuleaux triangular-shaped microcavity, where clockwise and counter traveling rays are classically separated. A period-5 exhibits chiral emission due to the asymmetric cavity shape. experimentally proved InGaAsP multi-quantum-well semiconductor laser by showing that experimental characteristics well coincide with wave dynamical ones.
We elucidate that Fermi resonance ever plays a decisive role in dynamical tunneling chaotic billiard. Interacting with each other through an avoided crossing, pair of eigenfunctions are coupled channels for tunneling. In this case, the islands chain and its unstable periodic orbit, which equals quantum number difference eigenfunctions. This phenomenon is confirmed quadrupole billiard relation resonance.
We report the first search for Sagittarius tidal stream of axion dark matter around $4.55\text{ }\text{ }\mathrm{\ensuremath{\mu}eV}$ using CAPP-12 TB haloscope data acquired in March 2022. Our result excluded Dine-Fischler-Srednicki-Zhitnitskii and Kim-Shifman-Vainshtein-Zakharov densities ${\ensuremath{\rho}}_{a}\ensuremath{\gtrsim}0.184$ $\ensuremath{\gtrsim}0.025\text{ }\mathrm{GeV}/{\mathrm{cm}}^{3}$, respectively, over a mass range from 4.51 to $4.59\text{ at 90% confidence level.
In an elliptic billiard, we find avoided level crossings taking place over wide ranges, which are of a Demkov type for generations eigenfunctions localized on islands chain and its pair unstable periodic orbit. For proof the existence crossings, first, show that quantized eigenvalue orbit, obtained by Einstein-Brillouin-Keller quantization rule, passes eigenvalues bouncing-ball modes orbit after so pairs sequentially generated. Next, using perturbed Hamiltonian, off-diagonal elements in...
Peers play an important role in individual’s learning via collaboration. This study examined three semesters worth of student data collected through collaborative exams a calculus-based introductory physics course. Participants were asked 142 problems over two rounds, and they answered the first individually (first round) then with their groups (second round). Based on group type determined by number correct answers, majority or incorrect variety answers individual round, we how affects...
Optical modes in deformed dielectric microdisk cavities often show an unexpected localization along unstable periodic ray orbits. We reveal a new mechanism for this kind of weakly cavities. In such systems the dynamics is nearly integrable and its phase space contains small island chains. When increasing deformation enlarging islands incorporate more modes. Each time mode comes close to border chain (separatrix) exhibits strong near corresponding orbit. Using EBK quantization scheme taking...
We report an axion dark matter search at Dine-Fischler-Srednicki-Zhitnitskii sensitivity with the CAPP-12TB haloscope, assuming axions contribute 100\% of local density. The excluded axion--photon coupling $g_{aγγ}$ down to about $6.2\times10^{-16}$ GeV$^{-1}$ over mass range between 4.51 and 4.59 $μ$eV a 90\% confidence level. achieved experimental can also exclude Kim-Shifman-Vainshtein-Zakharov that makes up just 13\% haloscope will continue wide masses.
Background:The scientific integrity, perceptions of misconduct, and students' needs in the research ethics education Korean Japanese gifted students were analyzed to address three questions. First, how well do practice their research? Second, perceive scientists' misconduct? Third, want learn what aspects they learn?Material methods:Participants comprised 397 370 science high school students.Results:Survey results showed that 48.92% 14.86% experienced misconduct regarding research. However,...
An energy shell structure depending on eccentricity is analyzed in a dielectric elliptic microcavity. Through the analysis, it explicated that governed by classical constant actions of periodic orbits. For clarification, relation between dominances orbits and bifurcation behaviors are obtained length spectra based eigenvalues computed numerical method compared with exact lengths analytic calculations. By matching effective wave numbers from orbit to stationary states closed open cavities, we...
The color conversion efficiency of phosphor films can be significantly improved by producing them in the shape photonic crystals (PhCs). When light with band‐edge wavelengths is incident on a PhCs film, excitation photons are resonantly absorbed, enhancing emission intensity. This study develops three‐dimensional PhC based self‐assembled inverse opal structures. phosphors constructed using silk fibroin polymer and red organic fluorescent dyes ( λ peak ≈ 610 nm) doped into it. structures...
High school students need more comprehensive scientific inquiry learning instruction through research ethics education. Yet, this topic is often overlooked in the science curriculum. To collect basic data to guide education for high students, study documents kinds of misconduct commit, contexts which they do so, and factors that influence such misconduct. Data were collected via questionnaires from 223 gifted at academies Korea. The results showed engaged most experiment-based classes rather...
CMOS image sensors for visible wavelength range have been receiving much attention over the last two decades, offering ultra-low power and camera-on-chip integration. Imagers are now able to extract additional information from scene thanks infrared sensing recognition or Time-of-Flight 3D imaging. Such capabilities enable an unlimited amount of applications in several businesses, i.e. automotive, industrial, life science, security, agricultural consumer. Imec has continuously developing...
Melton demonstrated a surprising disappearance using total internal reflection. When he put Florence flask filled with marbles into water tank and looked straight down from directly above the flask, was only able to see certain level. added more top line of marbles, all disappeared. He explained this phenomenon as due combination both refraction Here, we wanted develop idea create surprises. However, in our case, took effect Melton’s demonstrate magic. This is supported by various...
In this paper, a computational performance analysis is presented of wide-field time-gated fluorescence lifetime imaging microscope (FLIM) using practically realizable properties the laser, sample, and three-tap CMOS image sensor. The impact these component-level on accuracy precision measurement results are estimated discussed based Monte Carlo simulations. correlation between detector speed extracted studied, minimum required incident photoelectron number each pixel for different speeds...
Lens-free imaging (LFI) has become an important microscopy tool in many life science and industrial applications. Due to the absence of optical lenses (such as objectives) accompanying lens aberrations chromatic aberrations), LFI modality is well suited for inspection microscopic objects a wide spectral range. However, relatively restricted sensitivity CMOS imagers, i.e. from visible (~400 nm) up near-infrared range (~900 nm), limits use technique. Many samples contain valuable information...