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Observation and Numerical Simulations with Radar and Surface Data Assimilation for Heavy Rainfall over Central Korea

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Advances in Atmospheric Sciences 2011年第3期28卷 573-590页

作者： Ji-Hyun HA Hyung-woo KIM dong-Kyou lee Atmospheric Sciences Program School of Earth and Environmental SciencesSeoul National UniversitySeoul 151-747Korea

This study investigated the impact of multiple-Doppler radar data and surface data assimilation on forecasts of heavy rainfall over the central Korean Peninsula;the Weather Research and Forecasting(WRF) model and its three-dimensional variational data assimilation system(3DVAR) were used for this purpose. During data assimilation,the WRF 3DVAR cycling mode with incremental analysis updates(IAU) was used. A maximum rainfall of 335.0 mm occurred during a 12-h period from 2100 UTC 11 July 2006 to 0900 UTC 12 July *** radar data showed that the heavy rainfall was due to the back-building formation of mesoscale convective systems(MCSs).New convective cells were continuously formed in the upstream region,which was characterized by a strong southwesterly low-level jet(LLJ).The LLJ also facilitated strong convergence due to horizontal wind shear,which resulted in maintenance of the *** assimilation of both multiple-Doppler radar and surface data improved the accuracy of precipitation forecasts and had a more positive impact on quantitative forecasting(QPF) than the assimilation of either radar data or surface data *** back-building characteristic was successfully forecasted when the multiple-Doppler radar data and surface data were *** data assimilation experiments,the radar data helped forecast the development of convective storms responsible for heavy rainfall,and the surface data contributed to the occurrence of intensified low-level *** surface data played a significant role in enhancing the thermal gradient and modulating the planetary boundary layer of the model,which resulted in favorable conditions for convection.

关键词： radar and surface data data assimilation mesoscale convective system heavy rainfall

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Toward neglligible memories based heterostructures charge loss in on vertically charge injection integrated 2D

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Nano Research 2016年第8期9卷 2319-2326页

作者： dongri Qiu dong Uk lee Kyoung Su lee Sang woo Pak Eun Kyu Kim Quantum-Function Research Laboratory and Department of Physics Hanyang University Seou104763 Republic of Korea NAND Development Division NAND Product Engineering Group SK Hynix Icheon 17336 Republic of Korea

Two-dimensional （2D） crystals have a multitude of forms, including semi-metals, semiconductors, and insulators, which are ideal for assembling isolated 2D atomic materials to create van der Waals （vdW） heterostructures. Recently, artificially-stacked materials have been considered promising candidates for nanoelectronic and optoelectronic applications. In this study, we report the vertical integration of layered structures for the fabrication of prototype non-volatile memory devices. A semiconducting-tungsten-disulfide-channel-based memory device is created by sandwiching high-density-of-states multi-layered graphene as a carrier-confining layer between tunnel barriers of hexagonal boron nitride （hBN） and silicon dioxide. The results reveal that a memory window of up to 20 V is opened, leading to a high current ratio （〉103） between programming and erasing states. The proposed design combination produced layered materials that allow devices to attain perfect retention at 13% charge loss after 10 years, offering new possibilities for the integration of transparent, flexible electronic systems.

关键词： two-dimensional (2D)material graphene hexagonal boron nitride(hBN) tungsten disulphide (WS)2 heterostructure

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Spontaneous rupture of adrenal myelolipoma as a cause of acute flank pain:A case report

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World Journal of Clinical Cases 2021年第22期9卷 6552-6556页

作者： dong Soo Kim Jeong woo lee Sang Hyub lee Department of Urology School of MedicineKyung Hee UniversitySeoul 02447South Korea

BACKGROUND Adrenal myelolipoma is a rare,benign,non-functioning mass that occurs in the adrenal *** is composed of an admixture of hematopoietic elements and mature adipose tissue,similar to bone *** at large sizes,adrenal myelolipomas are usually asymptomatic and often incidentally found by ultrasonography or computed tomography(CT)*** paper describes an unusual case of adrenal myelolipoma presenting as flank *** SUMMARY A 50-year-old male with severe right flank pain underwent a CT scan revealing a huge mass extending into the suprarenal *** mass showed a fat component with retroperitoneal *** tumor was treated laparoscopically,and pathologic examination revealed features of myelolipoma originating from the adrenal *** Adrenal myelolipomas are generally asymptomatic and can be treated ***,rupture and hemorrhage of the tumor can cause symptoms requiring surgical removal.

关键词： Adrenal neoplasms Myelolipoma Adrenal glands Case report

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Radar Data Assimilation for the Simulation of Mesoscale Convective Systems

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Advances in Atmospheric Sciences 2010年第5期27卷 1025-1042页

作者： Jo-Han lee Hyun-Ha lee Yonghan CHOI Hyung-woo KIM dong-Kyou lee School of Earth and Environmental Sciences Seoul National University

A heavy rainfall case related to Mesoscale Convective Systems （MCSs） over the Korean Peninsula was selected to investigate the impact of radar data assimilation on a heavy rainfall forecast. The Weather Research and Forecasting （WRF） three-dimensional variational （3DVAR） data assimilation system with tuning of the length scale of the background error covariance and observation error parameters was used to assimilate radar radial velocity and reffectivity data. The radar data used in the assimilation experiments were preprocessed using quality-control procedures and interpolated/thinned into Cartesian coordinates by the SPRINT/CEDRIC packages. Sensitivity experiments were carried out in order to determine the optimal values of the assimilation window length and the update frequency used for the rapid update cycle and incremental analysis update experiments. The assimilation of radar data has a positive influence on the heavy rainfall forecast. Quantitative features of the heavy rainfall case, such as the maximum rainfall amount and Root Mean Squared Differences （RMSDs） of zonal/meridional wind components, were improved by tuning of the length scale and observation error parameters. Qualitative features of the case, such as the maximum rainfall position and time series of hourly rainfall, were enhanced by an incremental analysis update technique. The positive effects of the radar data assimilation and the tuning of the length scale and observation error parameters were clearly shown by the 3DVAR increment.

关键词： WRF 3DVAR 3DVAR cycling initialization tuning heavy rainfall radar data

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High-power and long-life supercapacitive performance of hierarchical, 3-D urchin-like W18049 nanostructure electrodes

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Nano Research 2016年第3期9卷 633-643页

作者： Sangbaek Park Hyun-woo Shim Chan woo lee Hee Jo Song Jae-Chan Kim dong-Wan Kim Department of Materials Science and Engineering Seoul National University Seoul 151-744 Republic of Korea School of Civil Environmental and Architectural Engineering Korea University Seou1136-713 Republic of Korea

We report the facile, one-pot synthesis of 3-D urchin-like W18O49 nanostructures （U-WO） via a simple solvothermal approach. An excellent supercapacitive performance was achieved by the U-WO because of its large Brunauer-Emmett- Teller （BET） specific surface area （ca. 123 m2.g-1） and unique morphological and structural features. The U-WO electrodes not only exhibit a high rate-capability with a specific capacitance （Csp） of -235 F·g-1 at a current density of 20 A.g-1, but also superior long-life performance for 1,000 cycles, and even up to 7,000 cycles, showing -176 F·g-1 at a high current density of 40 A.g-1.

关键词： hierarchical structure W18O49 high-power long cycle life supercapacitor

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Frequency comb-to-comb stabilization over a 1.3-km free-space atmospheric optical link

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Light(Science & Applications) 2022年第9期11卷 2207-2216页

作者： JAEWON YANG dong IL lee dong-CHEL SHIN JAEHYUN lee BYUNG SOO KIM HYUN JAY KANG YOUNG-JIN KIM SEUNG-woo KIM Department of Mechanical Engineering Korea Advanced Institute of Science and Technology(KAIST)291 Daehak-roYuseong-guDaejeon 34141Republic of Korea Presently with Korea Research Institute of Standards and Science(KRISS) 267 Gajeong-roYuseong-guDaejeon 34113Republic of Korea

Stabilizing a frequency comb to an ultra-stable optical frequency reference requires a multitude of optoelectronic peripherals that have to operate under strict ambient ***,the frequency comb-to-comb stabilization aims to synchronize a slave comb to a well-established master comb with a substantial saving in required equipment and ***,we report an utmost case of frequency comb-to-comb stabilization made through a 1.3 km free-space optical(FSO)link by coherent transfer of two separate comb lines along with a feedback suppression control of atmospheric phase *** FSO link offers a transfer stability of 1.7×10-15 at 0.1 s averaging,while transporting the master comb,s stability of 1.2×10-15 at 1.0 s over the entire spectrum of the slave *** remote comb-to-comb stabilization is intended to expedite diverse long-distance ground-to-ground or ground-to-satellite applications;as demonstrated here for broadband molecular spectroscopy over a 6THz bandwidth as well as ultra-stable microwaves generation with phase noise of-80dBc Hz-1 at 1 Hz.

关键词： optical stabilization microwave

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Molecular Mechanism of the Specificity of Protein Import into Chloroplasts and Mitochondria in Plant Cells

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Molecular Plant 2019年第7期12卷 951-966页

作者： dong wook lee Sumin lee Junho lee Seungjin woo Md.Abdur Razzak Alessandro Vitale Inhwan Hwang Division of Integrative Biosciences and Biotechnology Pohang University of Science and Technology Pohang 37673 Korea Department of Life Sciences Pohang University of Science and Technology Pohang 37673 Korea Istituto di Biologia e Biotecnologia Agraria Consiglio Nazionale Delle Ricerche Milano Italy

Plants possess both types of endosymbiotic organelles, chloroplasts and mitochondria. Transit peptides and presequences function as signal sequences for specific import into chloroplasts and mitochondria, respectively. However, how these highly similar signal sequences confer the protein import specificity remains elusive. Here, we show that mitochondrial- or chloroplast-specific import involves two distinct steps, specificity determination and translocation across envelopes, which are mediated by the N-terminal regions and functionally interchangeable C-terminal regions, respectively, of transit peptides and presequences. A domain harboring multiple-arginine and hydrophobic sequence motifs in the N-terminal regions of presequences was identified as the mitochondrial specificity factor. The presence of this domain and the absence of arginine residues in the N-terminal regions of otherwise common targeting signals confers specificity of protein import into mitochondria and chloroplasts, respectively. AtToc159, a chloroplast import receptor, also contributes to determining chloroplast import specificity. We propose that common ancestral sequences were functionalized into mitochondrial- and chloroplast-specific signal sequences by the presence and absence, respectively, of multiple-arginine and hydrophobic sequence motifs in the N-terminal region.

关键词： transit peptide presequence protein import into chloroplasts and mitochondria N-terminal specificity domain C-terminal common translocation domain import specificity determination

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Suspending Control Scheme of 8/10 Bearingless SRM Based on Adaptive Fuzzy PID Controller

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Chinese Journal of Electrical Engineering 2016年第2期2卷 60-67页

作者： Yingjie He Ying Tang dong-Hee lee Jin-woo Ahn Kyungsung University Busan Korea

As a nonlinear,strong coupling and multi-variable system,the drive performance of bearingless switched reluctance motor(BLSRM)is always limited by its complicated electromagnetic ***,conventional PID methods are used to achieve the basic control requirement in wide industrial applications,however its inherent operating principle limits its use on suspending control of *** this paper,the suspending force system,which is separately controlled from torque system,is built based on an adaptive fuzzy PID controller to limit the rotor eccentric displacement with proper generation of radial *** compared with a system adopted using conventional PID method for suspending force control,the proposed adaptive fuzzy PID method has superior performance in shortening the response time,reducing the maximum eccentric displacement error and higher speed range of operation due to its online self-turning of controller *** in simulation and experimental cases,comparison of results of the above two methods validates the effectiveness of the adaptive fuzzy PID controller for BLSRM drive system.

关键词： BLSRM suspending force control conventional PID controller adaptive fuzzy PID controlle

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Novel acoustic features for speech emotion recognition

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Science China(Technological Sciences) 2009年第7期52卷 1838-1848页

作者： ROH Yong-Wan KIM dong-Ju lee woo-Seok HONG Kwang-Seok School of Information and Communication Engineering Sungkyunkwan University300Chunchun-dongJangan-guSuwonKyungki-do440-746Korea Development Division / DSP Development Team Tamul Multimedia10th Fl.Anyang Trade Center1107Bisan-DongDongAn-GuAnyang-City431-050Korea

This paper focuses on acoustic features that effectively improve the recognition of emotion in human *** novel features in this paper are based on spectral-based entropy parameters such as fast Fourier transform(FFT) spectral entropy,delta FFT spectral entropy,Mel-frequency filter bank(MFB) spectral entropy,and Delta MFB spectral ***-based entropy features are *** reflect frequency characteristic and changing characteristic in frequency of *** implement an emotion rejection module using the probability distribution of recognized-scores and *** reduces the false recognition rate to improve overall ***-scores and rejected-scores refer to probabilities of recognized and rejected emotion recognition results,*** scores are first obtained from a pattern recognition *** pattern recognition phase uses the Gaussian mixture model(GMM).We classify the four emotional states as anger,sadness,happiness and *** proposed method is evaluated using 45 sentences in each emotion for 30 subjects,15 males and 15 *** results show that the proposed method is superior to the existing emotion recognition methods based on GMM using energy,Zero Crossing Rate(ZCR),linear prediction coefficient(LPC),and pitch *** demonstrate the effectiveness of the proposed *** of the proposed features,combined MFB and delta MFB spectral entropy improves performance approximately 10% compared to the existing feature parameters for speech emotion recognition *** demonstrate a 4% performance improvement in the applied emotion rejection with low confidence score.

关键词： speech emotion recognition MFB spectral entropy entropy emotion recognition rejection

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Diamond machining of sinusoidal grid surface using fast tool servo system for fabrication of hydrophobic surface

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中国有色金属学会会刊：英文版 2012年第S3期22卷 787-792页

作者： Hong LU Deug-woo lee Sang-Min lee Jeong-woo PARK Department of Nano Fusion Technology Pusan National University Department of Nano Mechatronics Engineering Pusan National University Department of Mechanical Design Engineering Chosun University

Ultra-precision diamond machining with piezoelectric-assisted fast tool servo (FTS) was used to produce various free-form surfaces.A low cost,rapid and large area fabrication of uniform hydrophobic surface at room temperature which transfers the FTS fabricated sinusoidal grid surface to the flat film with UV-moulding process was described.A piezoelectric-assisted FTS with high band width of 2 kHz,travel range up to 16 μm and the compact mechanism structure was designed for the sinusoidal grid surface machining and the dynamic performance testing of FTS was described in *** results indicate that the dimensions of sinusoidal grid change with the variation of the FTS machining *** properties of UV-moulded surface were evaluated,the best contact angle was measured to be 120.5° on the sinusoidal grid surface with profile wavelength of 350 μm and peak-to-valley amplitude of about 16 μm.

关键词： fast tool servo system diamond turning sinusoidal grid surface UV-moulding contact angle

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