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Effects of Hybrid Voltages on Oxide Formation on 6061 Al-alloys During Plasma Electrolytic Oxidation

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Chinese Journal of Aeronautics 2009年第5期22卷 564-568页

作者： Kai Wang Bon Heun Koo chan Gyu Lee young Joo Kim Sunghun Lee Eungsun Byon School of Nano & Advanced Materials Engineering Changwon National University Changwon 641-773 Korea Surface Technology Research Center Korea Institute of Materials Science Changwon 641-010 Korea

Plasma electrolytic oxidation （PEO） is carried out on 6061 Al-alloys in a weak alkaline electrolyte containing NaOH, Na2SiO3 and NaCl. Centered on the correlation of composition and structure, analyses by means of X-ray diffration （XRD）, scanning electron microscope （SEM） and energy dispersive spectrometry （EDS） are conducted on the specimens, which have been PEO-treated under hybrid voltages of different direct current （DC） values （140-280 V） with constant alternate current （AC） amplitude （200 V）. Attention is paid to the composition, properties and growth mechanism of oxide layers formed with hybrid voltages. Moreover, the main effects of DC value are discussed. Ceramic layers with a double-layer structure which combines hard outer and soft inner layers are found to be consist of α-Al2O3,γ-Al2O3 and mullite. With the DC values increasing, the growth of the ceramic layers tends to have increasingly obvious three-stage feature.

关键词： plasma electrolytic oxidation oxide layer aluminum alloys alkaline electrolyte hybrid voltages

Design of an 8 bit differential paired eFuse OTP memory IP reducing sensing resistance

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Journal of Central South University 2012年第1期19卷 168-173页

作者： JANG Ji-Hye 金丽妍 jeon Hwang-Gon KIM Kwang-Il HA Pan-Bong KIM young-Hee Department of Electronic Engineering Changwon National University9 Sarim-DongChangwon 641-773Korea

For the conventional single-ended eFuse cell, sensing failures can occur due to a variation of a post-program eFuse resistance during the data retention time and a relatively high program resistance of several kilo ohms. A differential paired eFuse cell is designed which is about half the size smaller in sensing resistance of a programmed eFuse link than the conventional single-ended eFuse cell. Also, a sensing circuit of sense amplifier is proposed, based on D flip-flop structure to implement a simple sensing circuit. Furthermore, a sensing margin test circuit is proposed with variable pull-up loads out of consideration for resistance variation of a programmed eFuse. When an 8 bit eFuse OTP IP is designed with 0.18 ~tm standard CMOS logic of TSMC, the layout dimensions are 229.04 μm ×100.15μm. All the chips function successfully when 20 test chips are tested with a program voltage of 4.2 V.

关键词： eFuse differential paired efuse cell one time programmable memory sensing resistance D flip-flop based sense amplifier

A New Infrared Atmospheric Sounding Interferometer channel Selection and Assessment of Its Impact on Met Office NWP Forecasts

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Advances in Atmospheric Sciences 2017年第11期34卷 1265-1281页

作者： young-chan NOH Byung-Ju SOHN. Yoonjae KIM Sangwon JOO William BELL Roger SAUNDERS School of Earth and Environmental Sciences Seoul National University Seou108826 Korea Numerical Modeling Center Korea Meteorological Administration Seou107062 Korea Met Office Exeter EXI 3PB United Kingdom

A new set of Infrared Atmospheric Sounding Interferometer （IASI） channels was re-selected from 314 EUMETSAT channels. In selecting channels, we calculated the impact of the individually added channel on the improvement in the analysis outputs from a one-dimensional variational analysis （1D-Var） for the Unified Model （UM） data assimilation system at the Met Office, using the channel score index （CSI） as a figure of merit. Then, 200 channels were selected in order by counting each individual channel＇s CSI contribution. Compared with the operationally used 183 channels for the UM at the Met Office, the new set shares 149 channels, while the other 51 channels are new. Also examined is the selection from the entropy reduction method with the same 1D-Var approach, Results suggest that channel selection can be made in a more objective fashion using the proposed CSI method. This is because the most important channels can be selected across the whole IASI observation spectrum. In the experimental trial runs using the UM global assimilation system, the new channels had an overall neutral impact in terms of improvement in forecasts, as compared with results from the operational channels. However, upper-tropospheric moist biases shown in the control run with operational channels were significantly reduced in the experimental trial with the newly selected channels. The reduction of moist biases was mainly due to the additional water vapor channels, which are sensitive to the upper-tropospheric water vapor.

关键词： Hyperspectral IR sounding channel selection 1D-Vat data assimilation

Effect of geogrid reinforcement on soft and medium dense soils

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Journal of Central South University 2011年第5期18卷 1638-1645页

作者： jeon Sang-Soo Department of Civil Engineering Construction Technology Research CenterINJE UniversityObang-dong 607KimhaeKyungsangnam-Do #621-749South Korea

The field tests were carried out to examine the reinforcement effect of a geogrid on various conditions of embankment height,the number of passages of vibratory roller,the number of reinforced layer of geogrid,and soil *** test results of the dynamic earth pressure indicate that the soil reinforced by geogrid is very effective to increase the stiffness of soil,especially in soft *** dynamic earth pressure ratio,which is defined as the ratio of dynamic earth pressure to self weight of soils,exponentially decreases as the embankment height *** dynamic earth pressure ratio increases up to 80% for soft soils reinforced by both one layer of geogrid in place of no reinforced soils and two layers in place of a single layer of geogrid.

关键词： dynamic earth pressure geogrid reinforced soils repetitive loading

Pull-out tests and slope stability analyses of nailing systems comprising single and multi rebars with grouted cement

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Journal of Central South University 2012年第1期19卷 262-272页

作者： Sang-Soo jeon Construction Technology Research Center Department of Civil EngineeringInje UniversityObang-dong 607KimhaeKyungsangnam-Do #621-749Korea

The pull-out capacities for soil nailing systems comprising of one single 29 mm diameter(type A) and four 16 mm diameter(type B) rebars with grouted cement were examined.A field test and numerical analysis for the type A and type B systems were carried out to investigate the pull-out capacities and the slope stability reinforcement efficiency in soil and rock *** results of the pull-out tests show the mobilized shear force and load transfer characteristics with respect to soil *** load-displacement relationship was examined for both type A and type B *** stability analyses were carried out to study the relationships between soil and nail reinforcement and bending stiffness as well as combined axial tension and shear *** of safety were calculated in relation to the number of nails and their outside *** soil and rock slopes were included in this evaluation.

关键词： soil nailing bending resistance pull-out test finite difference method

Damage Pattern Recognition of Spatially Distributed Slope Damages and Rainfall Using Optimal GIS Mesh Dimensions

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Journal of Mountain Science 2014年第2期11卷 336-344页

作者： Sang-Soo jeon Department of Civil & Urban Engineering Inje University

Damage assessment for slopes using geographical information system(GIS) has been actively carried out by researchers working on several government organizations and research institutes in Korea. In this study, 596 slope damages were examined to identify the types of damage associated with dip angles, dip directions, and heavy rainfall resulting from typhoons in South Korea. Heavy rainfall of 100 mm to 300 mm resulted in 80% at the investigated slope damages. A GIS database was developed for highways, rainfall, soil or rock geometry, and types of damage. A grid of rainfall intensity was generated from the records of maximum daily rainfall. Contours for slope damages and heavy rainfall using optimal GIS mesh dimensions were generated to visualize damage patterns and show substantially strong correlation of rainfall with slope damages. The combination of remote sensing with the GIS pattern recognition process described in this work are being expanded for a new generation of emergency response and rapid decision support systems.

关键词： Damage assessment Slope damages Rainfall GIS Typhoon

Roadbed behavior subjected to tilting-train loading at rail joint and continuous welded rail

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Journal of Central South University 2014年第7期21卷 2962-2969页

作者： jeon Sang-Soo Department of Civil&Urban Engineering Inje University

The tilting-train is very attractive to the railroad users in the world due to the advantage of high speed in curved track using pre-existing infrastructure of ***-train has a unique allowable speed and mechanism especially in curved *** this work,when tilting-train is operated with the allowable speed,the behavior of roadbed is evaluated by examining its settlement and bearing ***,the stability of roadbed is estimated as the roadbed is in the condition of soft soil influenced by the weather effects and cyclic train *** results show that the roadbed settlement satisfies the allowable settlement when the elastic moduli of upper roadbed and in-situ soil are greater than 3800 and 4600 kN/m2 for rail joint and 2300 and 3300 kN/m2 for continuous welded rail(CWR).

关键词： railway roadbed tilting-train bearing capacity settlement

Areas vulnerable to natural disasters and damage estimation of infrastructure in Busan, Korea

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Journal of Central South University 2014年第4期21卷 1499-1507页

作者： jeon Sang-Soo Department of Civil and Urban Engineering Inje University

Since the damages caused by disasters associated with climate anomalies and the diversification of the social structure increase every year, an efficient management system associated with a damage assessment of the areas vulnerable to disasters is demanded to prevent or mitigate the damages to infrastructure. The areas vulnerable to disasters in Busan, located at southeastern part of Korea, were estimated based on historical records of damages and a risk assessment of the infrastructure was performed to provide fundamental information prior to the establishment of the real-time monitoring system for infrastructure and establish disaster management system. The results are illustrated by using geographical information system(GIS) and provide the importance of the roadmap for comprehensive and specific strategy to manage natural disasters.

关键词： natural disaster damages risk assessment infrastructure disaster management system geographical information system

Longitudinal evolution of cortical thickness signature reflecting Lewy body dementia in isolated REM sleep behavior disorder:a prospective cohort study

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Translational Neurodegeneration 2023年第1期12卷 514-528页

作者： Jung Hwan Shin Heejung Kim Yu Kyeong Kim Eun Jin Yoon Hyunwoo Nam Beomseok jeon Jee-young Lee Department of Neurology Seoul Metropolitan Government-Seoul National University Boramae Medical Center and Seoul National University College of MedicineSeoulSouth Korea Department of Nuclear Medicine Seoul Metropolitan Government-Seoul National University Boramae Medical Center and Seoul National University College of MedicineSeoulSouth Korea Institute of Radiation Medicine Medical Research CenterSeoul National UniversitySeoulSouth Korea Department of Neurology Seoul National University Hospital and Seoul National University College of MedicineSeoulSouth Korea

Background The isolated rapid-eye-movement sleep behavior disorder(iRBD)is a prodromal condition of Lewy body disease including Parkinson’s disease and dementia with Lewy bodies(DLB).We aim to investigate the longitudinal evolution of DLB-related cortical thickness signature in a prospective iRBD cohort and evaluate the possible predictive value of the cortical signature index in predicting dementia-first phenoconversion in individuals with *** We enrolled 22 DLB patients,44 healthy controls,and 50 video polysomnography-proven iRBD *** underwent 3-T magnetic resonance imaging(MRI)and clinical/neuropsychological *** characterized DLB-related whole-brain cortical thickness spatial covariance pattern(DLB-pattern)using scaled subprofile model of principal components analysis that best differentiated DLB patients from age-matched *** analyzed clinical and neuropsychological correlates of the DLB-pattern expression scores and the mean values of the whole-brain cortical thickness in DLB and iRBD *** repeated MRI data during the follow-up in our prospective iRBD cohort,we investigated the longitudinal evolution of the cortical thickness signature toward Lewy body ***,we analyzed the potential predictive value of cortical thickness signature as a biomarker of phenoconversion in iRBD *** The DLB-pattern was characterized by thinning of the temporal,orbitofrontal,and insular cortices and relative preservation of the precentral and inferior parietal *** DLB-pattern expression scores correlated with attentional and frontal executive dysfunction(Trail Making Test-A and B:R=−0.55,P=0.024 and R=−0.56,P=0.036,respectively)as well as visuospatial impairment(Rey-figure copy test:R=−0.54,P=0.0047).The longitudinal trajectory of DLB-pattern revealed an increasing pattern above the cut-off in the dementia-first phenoconverters(Pearson’s correlation,R=0.74,P=6.8×10−4)but no significant change in parki

关键词： Rapid eye movement sleep behavior disorder Dementia with Lewy bodies Lewy body disease Cortical thickness Spatial covariance pattern Magnetic resonance imaging