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Journal of Materials Science & Technology 2022年第22期117卷 8-22页

作者： young-Kyun kim Kee-Ahn Lee Department of Materials Science and Engineering Inha UniversityIncheon 22212Republic of Korea Korea Institute of Materials Science(kimS) Changwon 51508Republic of Korea

High-entropy alloys(HEAs)with interstitial atoms that are produced by additive manufacturing have gained intensive interest in the materials science community because of their suitability for constructing high-strength net-shape ***,a strategy to additionally enhance the strength of selective laser melted carbon-containing HEAs was *** as-built carbon-containing HEAs(C_(x)(Cr_(20)Mn_(20)Fe_(20)Co_(20)Ni_(20))_(100-x)(x=0.5 at.%,1.0 at.%,and 1.5 at.%))contain supersaturated carbon,and the extent of supersaturation increases as the carbon content *** subjected to aging treatment at 650°C for 1 h,the microstructure of the three alloys did not change at the grain ***,the microstructure at the sub-grain scale changed markedly,and these changes influenced the tensile properties and deformation *** particular,the tensile strength of aged 1.5C-HEA at 650°C was∼1.2 GPa at room temperature,which is higher than those reported for CrMnFeCoNi ***,the main deformation mechanism changed from deformation twinning to dislocation-mediated slip,resulting in much higher strain hardening capacity after the aging *** work led to the development of an alternative promising method that involves tailoring the microstructure,to enhance the mechanical properties of additively manufactured metallic materials that contain interstitial atoms.

关键词： Selective laser melting High-entropy alloy Carbon contents Aging Microstructure evolution Tensile property Deformation mechanism

Robust fault detection of piecewise affine ARX systems

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Journal of Control and Decision 2020年第3期7卷 276-285页

作者： young-Man kim School of Engineering Liberty University1971 University Blvd.LynchburgVAUSA

In this paper,l1 regularisation-based robust fault detection technique for PWARX(PieceWise affine Auto Regressive eXogenous)systems is *** problem is formulated in convex optimisation form using l1 regularisation hence,global solution can be *** regularisation constant plays a key role for finding the number of *** MSE(mean square error)value between actual system and its model under no fault is used as a threshold for tracking dynamics change and detecting *** simplicity of turning only one parameter(regularisation constant)outstands this approach from *** proposed algorithm also shows the capability of separating the dynamics change from additive fault under *** illustration concludes this proposal by demonstrating its effectiveness.

关键词： Piecewise affine ARX fault detection regularisation convex optimisation sparsity

Cutoff characteristics of dielectric-filled circular holes embedded in dispersive plasmonic medium

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Chinese Optics Letters 2009年第10期7卷 904-908页

作者： Ki young kim Department of Physics National Cheng Kung University

The cutoff characteristics of dielectric-filled circular holes embedded in a dispersive plasmonic medium are investigated. Since two distinctive operating modes, surface plasmon polariton and circular waveguide modes, can exist in the slow and fast wave regions, respectively, the cutoff characteristics for each are separately investigated for linear and radial polarizations of the guided fields. As a result, the cutoff wavelengths for the linear and radial polarizations with very small subwavelength hole radii are found to be limited by the plasma resonance wavelength and plasma wavelength, which in turn are dependent and independent, respectively, of the dielectric constant of the dielectric filler material.

关键词： Circular waveguides Polarization Surface plasmon resonance

Evaluation of particle growth systems for sampling and analysis of atmospheric fine particles

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Particuology 2011年第6期9卷 606-610页

作者： Dae Seong kim Sang Bum Hong Jung-taek Kwon Kihong Park Department of Environmental Science and Engineering Gwangju Institute of Science and Technology Korea Polar Research Institute Laboratory of Toxicology College of Veterinary Medicine Seoul National University

Three types of water-based condensational growth systems, which can enable particles to grow in size to facilitate sampling and subsequent chemical analysis, were evaluated. The first one is a mixing type growth system where aerosols are mixed with saturated water vapor, the second one is a thermal diffusive growth system where warm flow enters cold-walled tube, and the third one is a laminar flow type where cold flow enters a warm wet-wall tube. Hygroscopic sodium chloride （NaCl）, ammonium sulfate （（NH4）2SO4） and ammonium nitrate （NH4N03）, and non-hygroscopic polystyrene latex （PSL） particles, in the size range of 50-400 nm, were used to determine their growth factors through the growth systems. Our data showed that the third-type growth system could enable particles to grow most efficiently regardless of their hygroscopic property. Collection efficiency of particles in the size range of 0.05-2.5 μm, in a continuous aerosol sampler after they passed through the third-type growth system was about 100%, suggesting that the third-type growth system would he the most useful among the tested growth systems for sampling and subsequent chemical analysis of fine and ultrafine particles.

关键词： Particle growth chamber Condensational growth Particle sampler Hygroscopic particles

Hepatobiliary scintigraphy for detecting biliary strictures after living donor liver transplantation

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World Journal of Gastroenterology 2011年第21期17卷 2626-2631页

作者： Yu Jin kim Kyu taek Lee young Cheol Jo Kwang Hyuck Lee Jong Kyun Lee Jae-Won Joh Choon Hyuck David Kwon Department of Medicine Samsung Medical CenterSungkyunkwan University School of Medicine Department of Surgery Samsung Medical CenterSungkyunkwan University School of Medicine

AIM:To investigate the diagnostic accuracy of hepatobiliary scintigraphy(HBS) in detecting biliary strictures in living donor liver transplantation(LDLT) ***:We retrospectively reviewed 104 adult LDLT recipients of the right hepatic lobe with duct-toduct anastomosis,who underwent HBS and *** HBS results were categorized as normal,parenchymal dysfunction,biliary obstruction,or bile leakage without *** presence of biliary strictures was determined by percutaneous cholangiography or endoscopic retrograde cholangiopancreatography(ERCP).RESULTS:In 89 patients with biliary strictures,HBS showed biliary obstruction in 50 and no obstruction in 39,for a sensitivity of 56.2%.Of 15 patients with no biliary strictures,HBS showed no obstruction in 11,for a specificity of 73.3%.The positive predictive value(PPV) was 92.6%(50/54) and the negative predictive value(NPV) was 22%(11/50).We also analyzed the diagnostic accuracy of the change in bile duct *** sensitivity,NPV,specificity,and PPV were 65.2%,27.9%,80% and 95%,***:The absence of biliary obstruction on HBS is not ***,when post-LDLT biliary strictures are suspected,early ERCP may be considered.

关键词： Living donor liver transplantation Tc99m mebrofenin Radionucleotide imaging Hepatobiliary scintigraphy Biliary stricture

Environmental Sound Event Detection in Wireless Acoustic Sensor Networks for Home Telemonitoring

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China Communications 2017年第9期14卷 1-10页

作者： Hyoung-Gook kim Jin young kim The Dept. of Electronics Convergence Engineering Kwangwoon University The Dept. of Electronics and Computer Engineering Chonnam National University

In this paper, we present an approach to improve the accuracy of environmental sound event detection in a wireless acoustic sensor network for home monitoring. Wireless acoustic sensor nodes can capture sounds in the home and simultaneously deliver them to a sink node for sound event detection. The proposed approach is mainly composed of three modules, including signal estimation, reliable sensor channel selection, and sound event detection. During signal estimation, lost packets are recovered to improve the signal quality. Next, reliable channels are selected using a multi-channel cross-correlation coefficient to improve the computational efficiency for distant sound event detection without sacrificing performance. Finally, the signals of the selected two channels are used for environmental sound event detection based on bidirectional gated recurrent neural networks using two-channel audio features. Experiments show that the proposed approach achieves superior performances compared to the baseline.

关键词： sound event detection wirelesssensor network gated recurrent neural net-work multichannel audio

1.45 GPa ultrastrong cryogenic strength with superior impact toughness in the in-situ nano oxide reinforced CrMnFeCoNi high-entropy alloy matrix nanocomposite manufactured by laser powder bed fusion

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Journal of Materials Science & Technology 2022年第2期97卷 10-19页

作者： young-Kyun kim Min-Chul kim Kee-Ahn Lee Department of Materials Science and Engineering Inha UniversityIncheon 22212Republic of Korea Korea Atomic Energy Research Institute(KAERI) Daejeon 34057Republic of Korea

CrMnFeCoNi high-entropy alloys(HEAs)exhibit an excellent combination of tensile strength and ductility at cryogenic *** study led to the introduction of a new method for the development of high-performance CrMnFeCoNi HEAs at cryogenic temperatures by jointly utilizing additive manufacturing(AM)and the addition of interstitial *** interstitial oxygen present in the powder feedstock was transformed into beneficial nano-sized oxides during AM *** HEA nanocomposite fabricated using laser powder bed fusion(L-PBF)not only contains heterogeneous grains and substructures but also a high number density of nano-sized *** tensile results revealed that the L-PBF HEA nanocomposite has superior yield strengths of 0.77 GPa and 1.15 GPa,and tensile strengths of 0.92 GPa and 1.45 GPa at 298 K and 77 K,*** addition,the Charpy impact energies of the samples tested at 298 K and 77 K were measured as 176.2 J and 103.7 J,*** results indicate that the L-PBF HEA nanocomposite successfully overcomes the well-known strength-toughness *** tensile deformation microstructure contained a relatively large number of deformation twins(DTs)at cryogenic temperature,a possible consequence of the decrease in the stacking fault energy with decreasing *** the other hand,cracks were found to propagate along the grain boundaries at room temperature,whereas a transgranular crack was observed at cryogenic temperature in the specimens fractured as a result of the Charpy impact.

关键词： Laser powder bed fusion High-entropy alloy matrix nanocomposite Nano-oxide:cryogenic Tensile Impact toughness

Suppression of DRR1 results in the accumulation of insoluble ubiquitinated proteins,which impairs drought stress tolerance

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Journal of Integrative Plant Biology 2021年第3期63卷 431-437页

作者： Seong Gwan Yu Na Hyun Cho Jong Hum kim Tae Rin Oh Woo taek kim Department of Systems Biology and Division of Life Science Yonsei UniversitySeoul 03722Korea Institute of Life Science and Biotechnology Yonsei UniversitySeoul 03722Korea

Drought stress has detrimental effects on *** the abscisic acid(ABA)-mediated drought response is well established,defensive mechanisms to cope with dehydration-induced proteotoxicity have been rarely ***1 was identified as an Arabidopsis drought-induced gene encoding an ER-localized RING-type E3 Ub *** of DRR1 markedly reduced tolerance to drought and proteotoxic stress without altering ABA-mediated germination and stomatal *** dehydration-induced insoluble ubiquitinated protein accumulation was more obvious in DRR1 loss-of-function plants than in wild-type *** results suggest that DRR1 is involved in an ABA-independent drought stress response possibly through the mitigation of dehydration-induced proteotoxic stress.

关键词： Arabidopsis drought stress E3 ligase proteotoxicity ubiquitination

Evaluation the Properties of Titanium Matrix Composites by Melting Route Synthesis

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Journal of Materials Science & Technology 2008年第1期24卷 105-109页

作者： Bong-Jae Choi Si-young Sung Myoung-Gyun kim young-Jig kim Department of Advanced Materials Engineering Sungkyunkwan University SuwonKorea Department of Advanced Materials Engineering Sungkyunkwan University SuwonKorea Materials & Processing Engineering CenterR&D DivisionKorea Automotive Technology InstituteChonanChungnamKorea Research Institute of Industrial Science and Technology Pohang Korea

The main purpose of this study is an in-situ synthesis of （TiB＋TiC） hybrid titanium matrix composites （TMCs） by vacuum induction melting method and to verify its mechanical *** melting route was adopted to synthesize the commercial pure titanium （cp Ti） and granular boron carbide （B-4C）.The reinforcements,the fraction of 10 ***,were formed by adding 1.88 wt pct B-4C to cp *** in-situ synthesis of TMCs,electron probe micro-analysis elemental mapping was carried out to confirm the distribution and shape of *** cone-on-disk type sliding wear test was also done for the identification of *** is concluded that （TiB＋TiC） hybrid TMCs can be in-situ synthesized and has better wear properties than H13.

关键词： Titanium matrix composites H13 In-situ Wear

High tibial osteotomy with human umbilical cord blood-derived mesenchymal stem cells implantation for knee cartilage regeneration

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World Journal of Stem Cells 2020年第6期12卷 514-526页

作者： Jun-Seob Song Ki-taek Hong Chae-Gwan Kong Na-Min kim Jae-Yub Jung Han-Soo Park young Ju kim Ki Bong Chang Seok Jung kim Department of Orthopedic Surgery Gangnam JS HospitalSeoul 06053South Korea Department of Orthopedic Surgery College of MedicineThe Catholic University of KoreaUijeongbu-si 11765South Korea Department of Nursing Education&Administration Uijeongbu St.Mary’s HospitalThe Catholic University of KoreaUijeongbu-si 11765South Korea

BACKGROUND High tibial osteotomy(HTO)is a well-established method for the treatment of medial compartment osteoarthritis of the knee with varus ***,HTO alone cannot adequately repair the arthritic joint,necessitating cartilage regeneration *** regeneration procedures with concomitant HTO are used to improve the clinical outcome in patients with varus *** To evaluate cartilage regeneration after implantation of allogenic human umbilical cord blood-derived mesenchymal stem cells(hUCB-MSCs)with concomitant *** Data for patients who underwent implantation of hUCB-MSCs with concomitant HTO were *** patients included in this study were over 40 years old,had a varus deformity of more than 5°,and a full-thickness International Cartilage Repair Society(ICRS)grade IV articular cartilage lesion of more than 4 cm2 in the medial compartment of the *** patients underwent second-look arthroscopy during hardware *** regeneration was evaluated macroscopically using the ICRS grading system in second-look *** also assessed the effects of patient characteristics,such as trochlear lesions,age,and lesion size,using patient medical *** A total of 125 patients were included in the study,with an average age of 58.3±6.8 years(range:43-74 years old);95(76%)were female and 30(24%)were *** average hip-knee-ankle(HKA)angle for measuring varus deformity was 7.6°±2.4°(range:5.0-14.2°).In second-look arthroscopy,the status of medial femoral condyle(MFC)cartilage was as follows:73(58.4%)patients with ICRS grade I,37(29.6%)with ICRS grade II,and 15(12%)with ICRS grade *** patients were staged with ICRS grade ***,the scores[except International Knee Documentation Committee(IKDC)at 1 year]of the ICRS grade I group improved more significantly than those of the ICRS grade II and III *** Implantation of hUCB-MSCs with concomitant HTO is an effective treatment for patients wit

关键词： Allogeneic Human umbilical cord blood-derived mesenchymal stem cells Cartilage regeneration High tibial osteotomy Osteoarthritic knees Arthroscopy