A5101441933- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Terahertz technology and applications
- Radio Frequency Integrated Circuit Design
- Photonic and Optical Devices
- Advanced Power Amplifier Design
- Advanced X-ray Imaging Techniques
- Superconducting Materials and Applications
- Radiation Therapy and Dosimetry
- Metallurgy and Material Forming
- Industrial Automation and Control Systems
- GaN-based semiconductor devices and materials
- Spectroscopy and Laser Applications
- Microstructure and Mechanical Properties of Steels
- Gyrotron and Vacuum Electronics Research
- Advanced Photonic Communication Systems
- MicroRNA in disease regulation
- Semiconductor materials and devices
- Nanofabrication and Lithography Techniques
- Advancements in Photolithography Techniques
- Extracellular vesicles in disease
- Photonic Crystal and Fiber Optics
- Laser-Plasma Interactions and Diagnostics
- High-pressure geophysics and materials
- Advanced Computational Techniques and Applications
Pohang Accelerator Laboratory
1991-2024
Pohang University of Science and Technology
2007-2024
Yonsei University
2024
SLAC National Accelerator Laboratory
2016-2021
Korea Post
2014
Korea Advanced Institute of Science and Technology
2000
Samsung (South Korea)
1998
Exosomes are enclosed compartments that released from cells and can transport biological contents for the purpose of intercellular communications. Research into exosomes is hindered by their rarity. In this article, we introduce a device uses centrifugal force filter with micro-sized pores to generate large quantity cell-derived nanovesicles. The has simple polycarbonate structure hold filter, operates in common centrifuge. Nanovesicles similar size membrane exosomes. contain intracellular...
The matter in extreme conditions end station at the Linac Coherent Light Source (LCLS) is a new tool enabling accurate pump–probe measurements for studying physical properties of high-energy density (HED) physics regime. This instrument combines world's brightest x-ray source, LCLS beam, with high-power lasers consisting two nanosecond Nd:glass laser beams and one short-pulse Ti:sapphire laser. These produce short-lived states high pressures, temperatures or densities that are important...
Guided-wave propagation of sub-ps terahertz (THz) pulses in a highly birefringent plastic photonic crystal fiber was studied by using THz time domain spectroscopy technique. The fabricated high density polyethylene tubes and solid filaments. fibers exhibit an extremely large birefringence ~ 2.1 x 10(-2), which is almost one order magnitude larger than that previously reported fibers.
This paper provides a design guide for optimum of an RF power amplifier with predistortion linearizer. For two-tone signal, three performance degradation factors, higher order terms, amplitude, and phase mismatches are analyzed quantitatively. The results implemented to the optimized WCDMA signal application. experiments, 2.4-GHz class-AB is fabricated using LDMOSFET 30-W peak envelope power. A simple third-order predistorter used measure relative phases harmonics, as well linearize...
A Doherty amplifier assisted by a supply modulator is presented using 2.14 GHz GaN HEMT saturated power (PA). novel envelope shaping method applied for high power-added efficiency (PAE) over broad output range. Experimental comparison with the and PAs carried out. For 8 dB crest factor WCDMA 1FA signal, PA supported presents improved PAE region compared to standalone PA. In addition, it achieves better than due lower signal At maximum average power, back-off from peak employing bias...
Abstract The nervous and immune systems are closely interconnected, influence the onset progress of various diseases. Accordingly, understanding interaction neural system becomes very important for treatment intractable diseases with analysis therapeutic mechanisms, such as autoimmune diseases, neurodegenerative cancers, so on. conventional immunomodulation treatments have been mainly carried out by drug administration, but they suffered from systemic negative side‐effects only limited...
Saliva contains biological information as blood and is recognized a valuable diagnostic medium for their noninvasiveness. Although "-omics" researches have tried to investigate saliva, the origin significance of its contents are not clear, usage largely confined oral disease in prognostic field. In an attempt broaden applicability saliva find systemic disease-derived RNA we made mouse models that had human melanoma isolated extracellular vesicles (EVs) from by aqueous 2-phase system (ATPS),...
This paper presents the required structure and function of a ring-FEL as radiation source for extreme ultraviolet lithography (EUVL). A 100 m-long straight section that conducts an extremely low emittance beam from fourth-generation storage ring can increase average power at 13.5 nm wavelength to up 1 kW without degrading in rest ring. Here, simulation results EUVL are described.
Summary form only given, as follows. A Doherty power amplifier (PA) for LTE applications is fully integrated on a 1.4mm × die using 2-um InGaP/GaAs HBT process. For signal with 7.5-dB PAPR and 10-MHz BW, the PA supply voltage of 4.5 V delivers PAE 36.3 %, an ACLR −32 dBc average output 27.5 dBm at frequency 1.85 GHz. Across 1.6–2.1 GHz, performs over 30 gain 28 dB below −31 dBm.
To find dominant 1/f noise sources, generalized analyses have been performed for self-aligned AlGaAs/GaAs heterojunction bipolar transistors (HBT's). For shorted base-emitter condition, the resistance fluctuation is dominant, while open current dominant. The collector-emitter noise, though generally considered an important source, negligible. stems mainly from emitter fluctuation. Our noise-reduction work focused on reduction of noise. We investigated base-emitter-current properties as a...
We suggest a new on-axis injection scheme that uses transverse deflecting rf cavity to kick the incoming beam into an already populated bucket but with timing offset from synchronous phase. In scheme, two cavities are required: one upstream of point crabs stored and other downstream both uncrabs kicks onto axis orbital plane. present theoretical analysis numerical simulations injected scheme.
Summary form only given, as follows. A multimode/multiband ET transmitter consisting of a hybrid switching amplifier (HSA) and broadband saturated PA is developed across 1.3 to 2.7 GHz. For the various standard signals, HSA efficiently provides supply signal by changing reference value hysteresis comparator. The PA, taking advantage nonlinear output capacitor shape voltage waveform, implemented based on load/source-pull methodology SRFT technique.
A multi-objective genetic algorithm (MOGA) is a powerful global optimization tool, but its results are considerably affected by the crossover parameter η c . Finding an appropriate demands too much computing time because MOGA needs be run several times in order to find good In this paper, self-adaptive introduced strategy adopt new for every generation while running MOGA. This scheme has also been adopted multi-generation Gaussian process (MGGPO) when producing trial solutions. Compared with...
Monitoring neural activity in the central nervous system often utilizes silicon-based microelectromechanical (MEMS) probes. Despite their effectiveness monitoring, these probes have a fragility issue, limiting application across various fields. This study introduces flexible printed circuit board (FPCB) characterized by robust mechanical and electrical properties. The demonstrate low impedance after platinum coating, making them suitable for multiunit recordings awake animals. capability...
This paper is a phenomenological qualitative study whose aim to explore the emotions and experiences Chat GPT-based integrated control of voice for English language learning experience twenty-threeKorean doctoral students. We intend demonstrate ways in which three students were exposed artificial intelligence-assisted technologies, they engaged with it between exposure emotional attachment, thus became emotionally tethered it. These findings show transition from uncertainty hope toward...
This paper presents the design of a compact gantry that uses superconducting bending magnets (BMs), for use in carbon-ion beam therapy. The size is comparable to those existing gantries are used proton-beam designed provides point-to-parallel scanning over an area $20\text{ }\text{ }\mathrm{cm}\ifmmode\times\else\texttimes\fi{}20\text{ }\mathrm{cm}$ at isocenter, and has rotationally invariant optics, which enabled by quadrupole dipole together with 90\ifmmode^\circ\else\textdegree\fi{}...
An online model is presented for the prediction of temperature distributions in bar roughing mill a hot strip mill. The consists an analytic interstand zone, and semianalytic bite zone. accuracy examined through comparison with predictions from finite element model.
We propose a terahertz (THz) confocal microscope. The THz field is modulated by dithering an objective lens, and the signal detected through pinhole. converted to image using analytic model based on perturbation analysis. can successfully predict surface profile of test sample. This confirms that proposed microscope has great potential for sample profiling in imaging system.
An investigation of the damping wiggler effect to reduce emittance in Pohang Accelerator Laboratory (PAL), a fourth-generation storage ring (4GSR) that uses multi-bend achromat, is presented. A 4GSR lattice which has reduced and increased dynamic aperture amplify synergy with two existing light sources (PLS-II PAL-XFEL) at PAL described.