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Comparison of Daily Extreme Temperatures over Eastern China and South Korea between 1996–2005

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Advances in Atmospheric Sciences 2009年第2期26卷 253-264页

作者：李红梅周天军 Jae-cheol nam State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences Meteorological Research Institute Korea Meteorological Administration

This paper examined the decadal mean, seasonal cycle, and interannual variations of mean and extreme temperatures using daily temperature and relative humidity data from 589 stations over eastern China and South Korea between 1996-2005. The results show that the decadal mean Tm （mean daily mean temperature） and the TNn （minimum daily minimum temperature） increase from north to south; the opposite spatial gradient is found in the DTR （diurnal temperature range）; the value of the DTR over South Korea is in- between that over North China and the mid-low Yangtze River valley; the TXx （maximum daily maximum temperature） has a unique spatial distribution, with the largest value over eastern China. The highest standard deviation （STD） is located over northern China and the TNn has the largest area coverage of the high STD. The peak of the seasonal cycle for the Tm, TXx and TNn over South Korea （August） occurs one month later than that over eastern China （July）. The seasonal cycle of the DTR has two peaks （April and October）; the value in the middle-lower reaches of the Yangtze River valley is larger than that in South Korea during July and August owing to the seasonal northward jump of the major monsoon rain band. The interannual variations of summertime temperature indices including the Tin, TXx, and DTR over South Korea are consistent （opposite） to that over northern （southern） China. For the wintertime temperature indices however, the variation over South Korea is consistent with that over eastern China.

关键词： extreme temperature indices decadal mean seasonal cycle interannual variation

UBP12/UBP13-mediated deubiquitination of salicylic acid receptor NPR3 suppresses plant immunity

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Molecular Plant 2023年第1期16卷 232-244页

作者： Yu Zhou Su-Hyun park nam-Hai Chua Temasek Life Sciences Laboratory National University of Singapore1 Research LinkSingapore 117604Singapore Disruptive&Sustainable Technologies for Agricultural Precision Singapore-MIT Alliance for Research and Technology1 CREATE WaySingapore 138602Singapore

Salicylic acid(SA),a defense hormone produced after pathogen challenge,is critical for plant *** NONEXPRESSER OF PR GENES 1(NPR1)and its paralogs NPR3 and NPR4 can bind SA and mediate SA signal ***1 functions as a transcriptional co-activator to promote defense gene expression,whereas NPR3 and NPR4 have been shown to function as negative regulators in the SA signaling *** the mechanism about NPR1 regulation has been well studied,how NPR3/NPR4 proteins are regulated in immune responses remains largely ***,we show that the stability of NPR3/NPR4 is enhanced by *** the absence of pathogen challenge,NPR3/NPR4 are unstable and degraded by the 26S proteasome,whereas the increase in cellular SA levels upon pathogen infection suppresses NPR3/NPR4 *** found that UBP12 and UBP13,two homologous deubiquitinases from a ubiquitin-specific protease subfamily,negatively regulate plant immunity by promoting NPR3/NPR4 *** genetic results further showed that UBP12/UBP13-mediated immunity suppression is partially dependent on NPR3/NPR4 *** interacting with NPR3 in the nucleus in an SA-dependent manner,UBP12 and UBP13 remove ubiquitin from polyubiquitinated NPR3 to protect it from being *** stabilization of NPR3/NPR4 promoted by UBP12/UBP13 is essential for negative regulation of basal and SA-induced immunity.

关键词： plant immunity salicylic acid NPR3 UBP12/UBP13

Comparison of Aerodynamic Forces and Moments Calculated by Three-dimensional Unsteady Blade Element Theory and Computational Fluid Dynamics

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Journal of Bionic Engineering 2017年第4期14卷 746-758页

作者： Loan Thi Kim Au Hoang Vu Phan Hoon cheol park Department of Advanced Technology Fusion and Artificial Muscle Research Center Konkuk University Seoul Korea

In previous work, we modified blade element theory by implementing three-dimensional wing kinematics and modeled the unsteady aerodynamic effects by adding the added mass and rotational forces. This method is referred to as Unsteady Blade Element Theory （UBET）. A comparison between UBET and Computational Fluid Dynamics （CFD） for flapping wings with high flapping frequencies （〉30 Hz） could not be found in literature survey. In this paper, UBET that considers the movement of pressure center in pitching-moment estimation was validated using the CFD method. We investigated three three-dimensional （3D） wing kinematics that produce negative, zero, and positive aerodynamic pitching moments. For all cases, the instantaneous aerodynamic forces and pitching moments estimated via UBET and CFD showed similar trends. The differences in average vertical forces and pitching moments about the center of gravity were about 10% and 12%, respectively. Therefore, UBET is proven to reasonably estimate the aerodynamic forces and pitching moment for flight dynamic study of FW-MAV. However, the differences in average wing drags and pitching moments about the feather axis were more than 20%. Since study of aerodynamic power requires reasonable estimation of wing drag and pitching moment about the feather axis, UBET needs further im- provement for hilzher accuracy.

关键词： blade element theory unsteady computational fluid dynamics flapping wings biomimetic

Longitudinal Flight Dynamic Analysis on Vertical Takeoff of a Tailless Flapping-Wing Micro Air Vehicle

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Journal of Bionic Engineering 2018年第2期15卷 283-297页

作者： Loan Thi Kim Au Vu Hoang Phan Hoon cheol park Department of Advanced Technology Fusion and Artificial Muscle Research Center Konkuk University Seou105029 Korea

This paper first analyzed the longitudinal dynamic behavior during vertical takeoff without control of a Flapping-Wing Micro Air Vehicle （FW-MAV）. The standard linear flight dynamics based on small disturbances from trim condition was not applicable for our analysis because the initial flight condition, which was at rest on the ground, could be such a large disturbance from the trim condition that the linearization is invalid. Therefore, we derived linearized Equations of Motion （EoM） which can treat an untrimmed flight condition as a reference for disturbances. The Computational Fluid Dynamic （CFD） software ANSYS Fluent was used to compute the aerodynamic forces and pitching moments. Three flight modes were found： a fast subsidence mode, a slow subsidence mode and a divergence oscil- latory mode. Due to divergence oscillatory mode, the deviation from the reference flight grew with time; the FW-MAV tumbled without control. The simulation showed for the first 0.5 second after leaving the ground （the time that is long enough for delay of feedback control）, the FW-MAV flew up to a height of 6 cm with small horizontal and pitching motion, which is close to a vertical flight.

关键词： bioinspired FW-MAV flight dynamics vertical takeoff CFD linear theory

Optimal Wing Rotation Angle by the Unsteady Blade Element Theory for Maximum Translational Force Generation in Insect-mimicking Flapping-wing Micro Air Vehicle

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Journal of Bionic Engineering 2016年第2期13卷 261-270页

作者： Loan Thi Kim Au Hoang Vu Phan Hoon cheol park Department of Advanced Technology Fusion Konkuk University Seoul 143-701 South Korea

This paper provides a parametric study to obtain the optimal wing rotation angle for the generation of maximum transla- tional force in an insect-mimicking Flapping-Wing Micro Air Vehicle （FWMAV） during hovering. The blade element theory and momentum theory were combined to obtain the equation from which the translational aerodynamic force could be esti- mated. This equation was converted into a non-dimensional form, so that the effect of normalized parameters on the thrust coefficient could be analyzed. The research showed that the thrust coefficient for a given wing section depends on two factors, the rotation angle of the wing section and the ratio of the chord to the travel distance of the wing section in one flapping cycle. For each ratio that we investigated, we could arrive at an optimal rotation angle corresponding to a maximum thrust coefficient. This study may be able to provide guidance for the FWMAV design.

关键词： FWMAV optimal rotation angle parametric study blade element theory momentum theory

The J-shape association of serum total IgE levels with age-related cataract

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International Journal of Ophthalmology(English edition) 2018年第6期11卷 1009-1012页

作者： Sangshin park nam-Kyong Choi Center for International Health Research Rhode Island Hospital the Warren Alpert Medical School of Brown University Department of Pediatrics the Warren Alpert Medical School of Brown University Department of Health Convergence Ewha Womans University

AIM： To address the association between serum total IgE levels and age-related cataract in adults. METHODS： The study participants consisted of 1052 adults aged 40y or older in the Korean National Health and Nutrition Examination Survey 2010. We performed multivariable logistic regression analyses using the quartile cut-points of total IgE levels. RESULTS： The odds ratios （ORs） for nuclear and any cataract with ≥267 kU/L of serum IgE levels were 1.75 [95% confidence intervals （CI）, 1.04-2.96] and 2.00 （95%CI, 1.22-3.27）, respectively, comparing to 35-87 kU/L. Interestingly, participants with ≤35 kU/L of IgE levels （OR, 1.67; 95%CI, 1.02-2.72） also had higher risk for any cataract than those with 35-87 kU/L. The risk for any cataract （OR, 1.48; 95%CI, 1.03-2.13） was higher in participants with high total IgE levels （〉150 kU/L）, comparing to normal participants. CONCLUSION： Our findings indicate a J-shaped relationship between serum IgE levels and age-related cataract.

关键词： IgE allergy cataract eye

Comprehensive analysis of two-dimensional charge transport mechanism in thin-film transistors based on random networks of single-wall carbon nanotubes using transient measurements

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Nano Research 2022年第2期15卷 1524-1531页

作者： Hyeonwoo Shin Sang-Joon park Byeong-cheol Kang Tae-Jun Ha Department of Electrical Engineering and Computer Science Inter-university Semiconductor Research CenterSeoul National UniversitySeoul 08826Korea Department of Electronic Materials Engineering Kwangwoon UniversitySeoul 01897Korea

Understanding charge transport mechanisms in thin-film transistors based on random networks of single-wall carbon nanotubes(SWCNT-TFTs)is essential for further advances to improve the potential for various nanoelectronic ***,a comprehensive investigation of the two-dimensional(2D)charge transport mechanism in SWCNT-TFTs is reported by analyzing the temperature-dependent electrical characteristics determined from the direct-current and non-quasi-static transient measurements at 80-300 *** elucidate the time-domain charge transport characteristics of the random networks in the SWCNTs,an empirical equation was derived from a theoretical trapping model,and a carrier velocity distribution was determined from the differentiation of the transient ***,charge trapping and de-trapping in shallow-and deep-traps in SWCNT-TFTs were analyzed by investigating charge transport based on their trapping/de-trapping *** comprehensive analysis of this study provides fundamental insights into the 2D charge transport mechanism in TFTs based on random networks of nanomaterial channels.

关键词： single-wall carbon nanotube random networks two-dimensional(2D)charge transport time-domain transient measurements charge trapping/de-trapping shallow-/deep-traps

Quasi-two-dimensional perovskite light emitting diodes for bright future

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Light(Science & Applications) 2021年第5期10卷 715-716页

作者： Jin-Wook Lee nam-Gyu park SKKU Advanced Institute of Nanotechnology(SAINT)and Department of Nanoengineering Sungkyunkwan UniversitySuwon 16419Republic of Korea School of Chemical Engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea

The fundamentals,promise and challenges of metal halide quasi-two-dimensional(quasi-2D)perovskites for a next generation emitter in light emitting diode devices are systematically reviewed.

关键词： diodes emitter emitting

Effects of PWHT on Microstructure and Mechanical Properties of Weld Metals of Ni-Based Superalloy 617 and 263 for Hyper-Supercritical Power Plants

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Acta Metallurgica Sinica(English Letters) 2016年第12期29卷 1107-1118页

作者： Jeong Kil Kim Hae Ji park Deog nam Shim Doosan Heavy Industries and Construction ChangwonGeongnam Korea

It is well known that solid solution-strengthened alloy 617 and γ′ precipitation-strengthened alloy 263 have excellent mechanical properties and corrosion resistance at high temperatures. Hyper-supercritical power plants work at temperatures above 700 ℃, and these superalloys are considered candidate materials for steam turbines components of these power plants. In this study, gas tungsten arc weldability of these superalloys was evaluated, and the effects of post- weld heat treatment （PWHT） on the microstructural characteristics and the mechanical properties of their weld metals were investigated. Scanning transmission electron microscopy, energy-dispersive spectroscopy and electron probe microanalysis were utilized for the investigation. The experimental results confirmed that these weld metals had different characteristics in microstructure and mechanical properties. PWHT resulted in the precipitation of intergranular carbides, γ′ particles and an increase in tensile strength of these superalloy weld metals. Furthermore, fine γ′ particles, which were not detected in the as-welded metal of alloy 263, were precipitated after PWHT and those particles were the reason for the drastic increase in tensile strength.

关键词： Superalloy Welding Precipitation Segregation