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Dispersal patterns of exotic forest pests in South Korea

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Insect Science 2012年第5期19卷 535-548页

作者： Won II choi Young-Seuk Park Division of Forest Disease and Insect Pests Korea Forest Research Institute Dongdaemun Seoul Department of Biology and The Korea Institute of Ornithology Kyung Hee University Dongdaemun Seoul Republic of Korea

Invasive species have potentially devastating effects on ecological communi- ties and ecosystems. To understand the invasion process of exotic forest pests in South Korea, we reviewed four major species of exotic forest pests： the pine needle gall midge （Thecodiplosis japonensis）, pine wilt disease caused by the pine wood nematode （Bur- saphelenchus xylophilus）, the fall webworm （Hyphantria cunea） and the black pine bast scale （Matsucoccus thunbergianae）. We consider their biology, ecology, invasion history, dispersal patterns and related traits, and management as exotic species. Among these species, the dispersal process of fall webworm was linear, showing a constant range expan- sion as a function of time, whereas the other three species showed biphasic patterns, rapidly increasing dispersal speed after slow dispersal at the early invasion stage. Moreover, human activities accelerated their expansion, suggesting that prevention of the artificial movement of damaged trees would be useful to slow expansion of exotic species. We believe that this information would be useful to establish management strategies for invasion species.

关键词： Bursaphelenchusxylophilus dispersal pattern exotic species fall webworm,forest management Hyphantria cunea Matsucoccus thunbergianae pine wilt disease,Thecodiplosis japonensis

Impact of Spectral Nudging on the Downscaling of Tropical Cyclones in Regional Climate Simulations

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Advances in Atmospheric Sciences 2016年第6期33卷 730-742页

作者： Suk-Jin choi Dong-Kyou LEE Atmospheric Sciences Program School of Earth and Environmental SciencesKorea-USA Weather and Climate Research Center Seoul National University

This study investigated the simulations of three months of seasonal tropical cyclone （TC） activity over the western North Pacific using the Advanced Research WRF Model. In the control experiment （CTL）, the TC frequency was considerably overestimated. Additionally, the tracks of some TCs tended to have larger radii of curvature and were shifted eastward. The large-scale environments of westerly monsoon flows and subtropical Pacific highs were unreasonably simulated. The overestimated frequency of TC formation was attributed to a strengthened westerly wind field in the southern quadrants of the TC center. In comparison with the experiment with the spectral nudging method, the strengthened wind speed was mainly modulated by large-scale flow that was greater than approximately 1000 km in the model domain. The spurious formation and undesirable tracks of TCs in the CTL were considerably improved by reproducing realistic large-scale atmospheric monsoon circulation with substantial adjustment between large-scale flow in the model domain and large-scale boundary forcing modified by the spectral nudging method. The realistic monsoon circulation took a vital role in simulating realistic TCs. It revealed that, in the downscaling from large-scale fields for regional climate simulations, scale interaction between model-generated regional features and forced large-scale fields should be considered, and spectral nudging is a desirable method in the downscaling method.

关键词： tropical cyclone spectral nudging technique dynamic downscaling regional climate simulation

Micro-precision surface finishing using magneto-rheological fluid

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Science China(Technological Sciences) 2012年第1期55卷 56-61页

作者： choi SeungBok LEE DeukWon LEE ChulHee Department of Mechanical Engineering Inha UniversityIncheon 402-751Korea

In order to improve the surface quality of machining workpiece, this paper studied a micro-precision surface finishing method by applying magneto-rheological fluid to the machined surface. A pin-on-disc testing apparatus was used to carry out surface finishing experiment of steel under different magnetic fields. Magneto-rheological fluid is colloidal suspension and stiffens in- to semi-solid when subjected to a magnetic field. Thus, the surface roughness of the finished surface could be controlled by magneto-rheological fluid under the different magnetic fields. Several sets of tests were performed with various normal loads, finishing speeds and magnetic fields. Removal rate was calculated by the removal loss monitored by testing apparatus, while microstmctures of the finished surface of pin and disk were observed by scanning electron microscope. The micro-precision roughness of finished surface was analyzed by surface profilorneter. The obtained test results showed different surface charac- teristics of the test material under different magnetic fields and proved the feasibility of this micro-precision surface finishing method to reduce the surface roughness of machining workpiece efficiently. At the same time, the effects of the various ap- plied normal loads and rotating speeds on the finishing surface by rnagneto-rheological fluid were investigated.

关键词： magnetorheological fluid surface fmishing removal rate surface roughness

A Fuzzy Shape Control Method for Stainless Steel Strip on Sendzimir Rolling Mill

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Journal of Iron and Steel Research International 2011年第3期18卷 17-23页

作者： HUR Yone-gi choi Young-kiu Technical Research Laboratories POSCO School of Electrical Engineering Pusan National University

The strip shape in the stainless steel process has made an issue of the strip *** objective of the shape control is to minimize the shape deviation and to maintain symmetrical shape patterns in the lateral *** method of the shape recognition employs the least square *** shape deviation is controlled by the fuzzy shape controller（FSC）.The experiments have been performed online for various stainless materials,thicknesses,and strip *** test results show very efficient performances in respect of stable target tracking and symmetrical and minimal fluctuation of the strip shape.

关键词： shape control fuzzy control stainless steel Sendzimir mill

Electrochemical processing of spent nuclear fuels:An overview of oxide reduction in pyroprocessing technology

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Progress in Natural Science:Materials International 2015年第6期25卷 572-582页

作者： Eun-Young choi Sang Mun Jeong Korea Atomic Energy Research Institute Department of Chemical Engineering Chungbuk National University

The electrochemical reduction process has been used to reduce spent oxide fuel to a metallic form using pyroprocessing technology for a closed fuel cycle in combination with a metal-fuel fast *** the electrochemical reduction process,oxides fuels are loaded at the cathode basket in molten LiO–LiCl salt and electrochemically reduced to the metal *** approaches based on thermodynamic calculations and experimental studies have been used to understand the electrode reaction and efficiently treat spent *** factors that affect the speed of the electrochemical reduction have been determined to optimize the process and scale-up the electrolysis *** addition,demonstrations of the integrated series of processes(electrorefining and salt distillation) with the electrochemical reduction have been conducted to realize the oxide fuel *** overview provides insight into the current status of and issues related to the electrochemical processing of spent nuclear fuels.

关键词： Pyroprocessing Electrochemical reduction Electrorefining Molten salt Spent oxide fuel

Enhancing BiVO_(4)photoanode performance by insertion of an epitaxial BiFeO_(3)ferroelectric layer

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Journal of Energy Chemistry 2024年第2期89卷 71-78,I0003页

作者： Haejin Jang Yejoon Kim Hojoong choi Jiwoong Yang Yoonsung Jung Sungkyun choi Donghyeon Lee Ho Won Jang Sanghan Lee School of Materials Science and Engineering Gwangju Institute of Science and TechnologyGwangju 61005Republic of Korea Department of Materials Science and Engineering Seoul National UniversitySeoul 08826Republic of Korea

BiVO_(4)(BVO)is a promising material as the photoanode for use in photoelectrochemical ***,the high charge recombination and slow charge transfer of the BVO have been obstacles to achieving satisfactory photoelectrochemical *** address this,various modifications have been attempted,including the use of ferroelectric *** materials can form a permanent polarization within the layer,enhancing the separation and transport of photo-excited electron-hole *** this study,we propose a novel approach by depositing an epitaxial BiFeO_(3)(BFO)thin film underneath the BVO thin film(BVO/BFO)to harness the ferroelectric property of *** self-polarization of the inserted BFO thin film simultaneously functions as a buffer layer to enhance charge transport and a hole-blocking layer to reduce charge *** a result,the BVO/BFO photoanodes showed more than 3.5 times higher photocurrent density(0.65 mA cm^(-2))at 1.23 V_(RHE)under the illumination compared to the bare BVO photoanodes(0.18 m A cm^(-2)),which is consistent with the increase of the applied bias photon-to-current conversion efficiencies(ABPE)and the result of electrochemical impedance spectroscopy(EIS)*** results can be attributed to the self-polarization exhibited by the inserted BFO thin film,which promoted the charge separation and transfer efficiency of the BVO photoanodes.

关键词： Photoelectrochemical Photoanode BiVO_(4) Ferroelectric materials BiFeO_(3)

Antidepressant-Like Effects of Hesperidin in Animal Model of Post-Traumatic Stress Disorder

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Chinese Journal of Integrative Medicine 2021年第1期27卷 39-46页

作者： Bombi Lee Gwang Muk choi Bongjun Sur Acupuncture and Meridian Science Research Center College of Korean MedicineKyung Hee UniversitySeoul(02447)Republic of Korea Center for Converging Humanities Kyung Hee UniversitySeoul(02447)Republic of Korea The Graduate School of Basic Science of Medicine College of MedicineKyung Hee UniversitySeoul(02447)Republic of Korea Dopartmont of Molcoular Mcdicine and TIDRC School of MedicineEwha Womans UniversitySeoul(07985)Republic of Korea

Objective:Post-traumatic stress disorder(PTSD)is a psychiatric disorder characterized by depression and anxiety,that arises due to an imbalance of neurotransmitters in response to excessive ***(HSD)is a naturally occurring flavonoid shown to exert a variety of biological activities,including antioxidant,anti-inflammatory,and neuroprotective ***:This study was used the open field test(OFT)and forced swimming test(FST)to examine the effects of HSD on the depression-like response of rats after exposure to a single prolonged stress(SPS)leading to the dysregulation of the serotonergic activation *** rats were given HSD(20,50,and 100 mg/kg,intraperitoneal injection,n=6–7 per group)once daily for 14 days after exposure to *** influence of administration of HSD on SPS-induced behavioral responses and concentrations of serotonin(5-HT),5-hydroxyindoleacetic acid(5-HIAA),and monoamine oxidase-A(MAO-A)in the rat brain were also investigated using enzyme-linked immunoassays(ELISAs).Results:Daily HSD administration significantly improved depression-like behaviors in the FST(P<0.05),increased the number of lines crossed in the central zone of the OFT(P<0.01),and reduced freezing behavior both in contextual and cued fear *** treatment also attenuated the reduction in SPS-induced 5-HT concentrations in the hippocampus and *** increase in 5-HT concentrations during HSD treatment was partially attributed to a decrease in the 5-HIAA/5-HT ratio in the hippocampus of rats with ***,HSD treatment inhibited activity of MAO-A and decreases of tryptophan hydroxylase-1 expression in the ***:HSD was shown to exert antidepressant effects in rats exposed to SPS,suggesting that this natural flavonoid may be an effective medicine for PTSD.

关键词： hesperidin post-traumatic stress disorder depression serotonin

Optical coherence tomography imaging of cranial meninges post brain injury in vivo

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Chinese Optics Letters 2017年第9期15卷 16-19页

作者： Woo June choi Ruikang K.Wang Department of Bioengineering University of WashingtonSeattleWA 98195USA

We report a new application of optical coherence tomography（OCT） to investigate the cranial meninges in an animal model of brain injury in vivo. The injury is induced in a mouse due to skull thinning, in which the repeated and excessive drilling exerts mechanical stress on the mouse brain through the skull, resulting in acute and mild brain injury. Transcranial OCT imaging reveals an interesting virtual space between the cranial meningeal layers post skull thinning, which is gradually closed within hours. The finding suggests a promise of OCT as an effective tool to monitor the mechanical trauma in the small animal model of brain injury.

关键词： Optical coherence tomography imaging of cranial meninges post brain injury in vivo

Change in Childcare Policy and Defamilialization

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学术界 2017年第11期 257-267页

作者： Mihyang choi Sungkyunkwan University

This study explores childcare policy change in South Korea by employing the gradual institutional change model and in relation to the concept of defamilialization.T his study measured the degree of defamilialization quantitatively using the data of Childcare Statistics between 2001-2016 and conducted hierarchical cluster *** analysis results showed that the trajectories of childcare policy in South Korea could be divided into three clusters-2001-2006 for the first cluster,2007-2012 for the second cluster,and2013-2016 for the third cluster-and there were two changes-conversion and *** policy in South Korea has taken the path of familialization,market defamilialization,and active familialization.

关键词： childcare policy policy change defamilialization South Korea