A5101937877- Atmospheric Ozone and Climate
- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Air Quality Monitoring and Forecasting
- Photonic and Optical Devices
- Advanced Fiber Laser Technologies
- Water Quality Monitoring and Analysis
- Advanced Photonic Communication Systems
- Advancements in Semiconductor Devices and Circuit Design
- Semiconductor Lasers and Optical Devices
- Semiconductor materials and devices
- Low-power high-performance VLSI design
- Nonlinear Optical Materials Research
- CCD and CMOS Imaging Sensors
- Ferroelectric and Negative Capacitance Devices
- Advanced MEMS and NEMS Technologies
- Advanced Measurement and Detection Methods
- Ultrasonics and Acoustic Wave Propagation
- Acoustic Wave Resonator Technologies
- Integrated Circuits and Semiconductor Failure Analysis
- Ionosphere and magnetosphere dynamics
- Infrared Target Detection Methodologies
- Educational and Technological Research
- Atmospheric aerosols and clouds
- VLSI and Analog Circuit Testing
Pusan National University
2011-2023
Samsung (South Korea)
2014-2020
University of Minnesota
2002-2004
The Geostationary Environment Monitoring Spectrometer (GEMS) is scheduled for launch in February 2020 to monitor air quality (AQ) at an unprecedented spatial and temporal resolution from a geostationary Earth orbit (GEO) the first time. With development of UV–visible spectrometers sub-nm spectral sophisticated retrieval algorithms, estimates column amounts atmospheric pollutants (O3, NO2, SO2, HCHO, CHOCHO, aerosols) can be obtained. To date, all satellite missions monitoring have been low...
With the explosive growth of battery-operated portable devices, demand for low power and small size has been increasing system-on-a-chip (SoC). The FinFET is considered as one most promising technologies future low-power mobile applications because its good scaling ability, high on-current, better SCE subthreshold slope, leakage current [1]. As a key approach low-power, supply-voltage (V<inf>DD</inf>) widely used in SoC design. However, SRAM limiting factor voltage-scaling, since all...
Two 128 Mb dual-power-supply SRAM chips are fabricated in a 14 nm FinFET technology. A 0.064 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\mu$</tex> </formula> m Notation="TeX">$^{2}$</tex> and 0.080 6T bitcells designed for high-density (HD) high-performance (HP) applications. To improve Notation="TeX">${\rm V}_{{\rm MIN}}$</tex></formula> of the SRAM, negative bitline scheme (NBL) is adopted as...
Abstract. The continued interest in air pollution and stratospheric ozone variability has motivated the development of a Geostationary Environmental Monitoring Spectrometer (GEMS) for hourly monitoring. This paper provides atmospheric science community with world's first assessment GEMS total column (TCO) retrieval performance diurnal variation. algorithm used is more advanced version its predecessor, Total Ozone Mapping (TOMS) V8, that incorporates several improvements, including new lookup...
Abstract. As all life on earth depends crucially atmospheric ozone, low orbiting (LEO) satellites have been used to monitor ozone reduce its impact the environment and public health. The continued interest in air pollution stratospheric variability has motivated development of a geostationary environmental monitoring satellite (GEMS) for hourly monitoring. This paper provides science community with world's first assessment GEMS total column (TCO) retrieval performance diurnal variation....
This paper presents a novel approach to enable real-time device simulation and optimization. State-of-the-art algorithms which can describe semiconductor domain are adopted train deep learning models whose input output process condition doping profile / electrical characteristic, respectively. Our framework enables update automatically by estimating the uncertainty of model prediction. Real-Time TCAD is validated on 130nm processes for display driver integration circuit (DDI), 1) prediction...
Abstract. Most previous evaluations of satellite performance relied on pair wise comparisons with limited spatial and temporal coverage surface-based measurements such as soundings in-situ measurements. Especially, validation HCHO is very difficult because ground-based are extremely sparse. We use a new scientific approach, statistical analyses empirical orthogonal function (EOF) singular value decomposition (SVD), to provide three-dimensional results global picture over long measurement...
The statistical tools such as empirical orthogonal function (EOF), and singular value decomposition (SVD) have been applied to analyze the characteristic of air pollutant over southeast Asia well evaluate Zimeke's tropospheric column ozone (ZTO) determined by residual method. In this study, we found that EOF SVD analyses are useful methods extract most significant temporal spatial pattern from enormous amounts satellite data. with OMI <TEX>$NO_2$</TEX> HCHO revealed showed high correlation...
We have found an error in the operational OMI HCHO columns, and corrected it by applying a background parameterization derived on 4th order polynomial fit to time series of monthly average data. The agrees with this understanding as well other sensors measurements has no unrealistic trends. A new scientific approach, statistical analyses EOF SVD, was adapted reanalyze consistency satellite HCHO, CO, NO 2 , fire counts over Africa. SVD MOPITT SCIAMAHCY, show overall spatial temporal pattern...
Slanted finger SAW transducers allow one to design wide band filters with excellent characteristics. One of the most interesting modifications such a filter is slanted SPUDT. We present an approach analysis based on consistent use Y-matrix instead conventional P-matrix. Conditions optimal matching SPUDT are obtained and examples method developed for shown.
위성영상을 이용하여 산출된 대기운동벡터(AMV)와 라디오존데 바람 관측 자료를 이용한 검증결과는 AMV가 지속적으로 자료에 비해서 풍속이 약하게 나타나는 Slow Speed Bias(SSB)를 보여 주었다. 이러한 SSB는 표적추적, 표적선정, 그리고 고도할당 단계의 오차에 의해 야기될 수 있으며, 이 중 오차는 SSB를 발생시키는 주된 요인으로 여겨진다. 그러나 최근 연구에서는 개선만으로는 SSB 문제를 해결하는데 한계가 있음을 밝혔다. 그러므로 본 새로운 표적추적 알고리듬을 개발하여 감소시킴으로서 기상청 현업 AMV 알고리듬의 성능을 개선하고자 하였다. 표적 내에 다양한 시 공간 규모의 바람이 포함되어 벡터가 과도하게 평균된 움직임으로 계산되거나, 구름이 추적 시간동안 형태를 유지하지 못하고 변형되는 경우에 발생한다. 해결하기 위해 개발된 알고리듬에서는 가우시안 군집분석(GMM)을 변형이 적고 추적에 용이한 저온 군집을 표적으로 재선정하고, 이미지를 변형시켜 군집의...
Summary form only given. We have demonstrated that the design of directional-coupler modulator may be synthesized to obtain desired response functions, so modulators with high linearity in function or low switching voltage realized.
The presences of clouds significantly influence the accuracy ozone retrievals from satellite measurements. This study focuses on Ozone Monitoring instrument (OMI) profile retrieval based an optimal estimation. There are two operational OMI cloud products; OMCLDO2, absorption in <TEX>$O_2-O_2$</TEX> at 477 nm, and OMCLDRR, filling Fraunhofer lines by rotational Raman scattering (RRS) 350 nm. Firstly, we characterize differences between RRS effective pressures using MODIS optical thickness...
Ozone&#160;in the troposphere is an important&#160;air&#160;pollutant and greenhouse gas, also acts as a principal oxidant in lower atmosphere. This ozone not emitted directly from anthropogenic sources, but formed though photochemical reaction of nitrogen oxides with hydrocarbons presence heat sunlight. Ozone its precursor can be transported across&#160;continents&#160;and to&#160;the&#160;oceans. As well, downward transport stratosphere plays important role...