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Densification simulation of compacted Al powders using multi-particle finite element method

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中国有色金属学会会刊：英文版 2009年第B09期19卷 68-75页

作者： Kyung-Hun LEE jung-min LEE Byung-min KIM School of Mechanical Engineering Pu san National University

The powder compaction simulations were performed to demonstrate deformation behavior of particles and estimate the effect of different punch speeds and particle diameters on the relative density of powder by a multi-particle finite element model(MPFEM). Individual particle discretized with a finite element mesh allows for a full description of the contact mechanics. In order to verify the reliability of compaction simulation by MPFEM, the compaction tests of porous aluminum with average particle size of 20 μm and 3 μm were performed at different ram speeds of 5, 15, 30 and 60 mm/min by MTS servo-hydraulic tester. The results show that the slow ram speed is of great advantage for powder densification in low compaction force due to sufficient particle rearrangement and compaction force increases with decrease in average particle size of aluminum.

关键词：粉末压实粉末粒子多孔铝有限元法模拟致密化平均粒径有限元模型

Optimal Checkpoint Placement on Real-Time Tasks with Harmonic Periods

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Journal of Computer Science & Technology 2012年第1期27卷 105-112页

作者： Seong Woo Kwak jung-min Yang Department of Electronic Engineering Keimyung University Department of Electrical Engineering Catholic University of Daegu

This paper presents an optimal checkpoint strategy for fault-tolerance in real-time systems where transient faults occur in Poisson distribution. In our environment, multiple real-time tasks with different deadlines and harmonic periods are scheduled in the system by rate-monotonic algorithm, and checkpoints are inserted at a constant interval in each task. When a fault is detected, the system carries out rollback to the latest checkpoint and re-executes tasks. The maximum number of re-executable checkpoints and an equation to check schedulability are derived, and the optimal number of checkpoints is selected to maximize the probability of completing all the tasks within their deadlines.

关键词： checkpoint scheme real-time system fault-tolerance harmonic period rate-monotonic (RM) scheduling

Recent trends in the epidemiology and clinical outcomes of inflammatory bowel disease in South Korea,2010-2018

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World Journal of Gastroenterology 2024年第9期30卷 1154-1163页

作者： Seulji Kim Hyun jung Lee Seung Woo Lee Sanghyun Park Seong-Joon Koh Jong Pil Im Byeong Gwan Kim Kyung-Do Han Joo Sung Kim Department of Internal Medicine Korea Institute of Radiological and Medical SciencesSeoul 01812South Korea Department of Internal Medicine and Liver Research Institute Seoul National University College of MedicineSeoul 03080South Korea Department of Statistics and Actuarial Science Soongsil UniversitySeoul 06978South Korea

BACKGROUND Inflammatory bowel disease(IBD)was previously regarded as a Western disease;however,its incidence is increasing in the *** epidemiology of IBD in Asia differs significantly from the patterns in the *** To comprehensively investigate the epidemiology of IBD in South Korea,inclu-ding its incidence,prevalence,medication trends,and *** We analyzed claims data from the Health Insurance Review and Assessment Service and Rare and Intractable Diseases(RIDs),operated by the National Health Insurance Service of South *** with IBD were identified based on the International Classification of Diseases,Tenth Revision,and RID diagnostic codes for Crohn’s disease(CD)and ulcerative colitis(UC)from 2010 to *** In total,14498 and 31409 patients were newly diagnosed with CD and UC,respectively,between 2010 and *** annual average incidence of CD was 3.11 cases per 105 person-years,and that of UC was 6.74 cases per 10^(5) *** 2014,the incidence rate of CD has been stable,while that of UC has steadily increased,shifting the peak age group from 50-year-olds in 2010 to 20-year-olds in *** CD and UC prevalence increased consistently over the study period;the use of 5-aminosali-cylates and corticosteroids gradually decreased,while that of immunomodulators and biologics steadily increased in both CD and *** clinical outcomes of IBD,such as hospitalization and surgery,decreased during the study *** The CD incidence has been stable since 2014,but that of UC has increased with a shift to a younger age at peak incidence between 2010 and *** clinical outcomes improved over time,with increased use of immunomodu-lators and biologics.

关键词： Inflammatory bowel disease Crohn’s disease Ulcerative colitis Incidence Prevalence

Intrinsic electrochemical activity of Ni in Ni_(3)Sn_(4) anode accommodating high capacity and mechanical stability for fast-charging lithium-ion batteries

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Journal of Energy Chemistry 2022年第8期31卷 470-477,I0013页

作者： Janghyuk Moon Trung Dinh Hoang Seong Soo Park Seowan Park Dong Young Rhee Junwon Lee Sang A Han min-sik Park jung Ho Kim School of Energy Systems Engineering Chung-Ang UniversityHeukseok-RoDongjak-guSeoul 06974Republic of Korea Department of Advanced Materials Engineering for Information and Electronics Integrated Education Institute for Frontier Science&Technology(BK21 Four)Kyung Hee University1732 Deogyeong-daeroGiheung-guYongin 17104Republic of Korea Institute for Superconducting&Electronic Materials(ISEM) Australian Institute of Innovative Materials(AIIM)University of WollongongInnovation CampusSquires WayNorth WollongongNSW 2500Australia

Fast interfacial kinetics derived from bicontinuous three-dimensional(3D)architecture is a strategic feature for achieving fast-charging lithium-ion batteries(LIBs).One of the main reasons is its large active surface and short diffusion ***,understanding of unusual electrochemical properties still remain great challenge due to its *** this study,we proposed a nickel–tin compound(Ni_(3)Sn_(4))supported by 3D Nickel scaffolds as main frame because the Ni_(3)Sn_(4) clearly offers a higher reversible capacity and stable cycling performance than bare tin(Sn).In order to verify the role of Ni,atomic-scale simulation based on density functional theory systematically addressed to the reaction mechanism and structural evolution of Ni_(3)Sn_(4) during the lithiation *** findings are that Ni enables Ni_(3)Sn_(4) to possess higher mechanical stability in terms of reactive flow stress,subsequently lead to improve Li storage *** study elucidates an understanding of the lithiation mechanism of Ni_(3)Sn_(4) and provides a new perspective for the design of high-capacity and high-power 3D anodes for fast-charging LIBs.

关键词： Lithium-ion batteries Ni_(3)Sn_(4) High-capacity anode 3D-structured electrode Inverse opal structure Density functional theory

Production of chitosan-based composite film reinforced with lignin-rich lignocellulose nanofibers from rice husk

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Journal of Bioresources and Bioproducts 2024年第2期9卷 174-184页

作者： Hye Jee Kang Yeon Ju Lee Jin Kyoung Lee Irnia Nurika Sri Suhartini Deokyeong Choe Dong Hyun Kim Hoon Choi Natasha P.Murphy Ho Yong Kim Young Hoon jung School of Food Science and Biotechnology Kyungpook National UniversityDaegu 41566Republic of Korea CPR S&T Co. Ltd.Gunpo 15880Republic of Korea Department of Agroindustrial Technology Faculty of Agricultural TechnologyUniversitas BrawijayaMalang 65145Indonesia Renewable Resources and Enabling Sciences Center National Renewable Energy LaboratoryGoldenCO 80401United States Center for Bio-based Chemistry Korea Research Institute of Chemical TechnologyUlsan 44429Republic of Korea

Lignocellulosic nanofibers(LCNFs),implying lignin-containing cellulose fibers,maintain the prop-erties of both lignin and cellulose,which are hydrophobic and hydrophilic,*** pres-ence of hydrophobic lignin in LCNFs is expected to be an economical and attractive option that can improve the thermal and mechanical properties of ***,this study was conducted to produce lignin-rich LCNFs from sugar-rich waste obtained from rice husks after acidic *** LCNFs were produced from the lignin-rich solid fractions obtained after pretreatment and enzymatic hydrolysis,which were then incorporated as an additive into a chitosan-based *** variations in lignin content in the range of approximately 50.6%-66.8%in differently obtained LCNFs gave significantly different optical strengths and mechanical *** controllable processes may allow for customized film ***,the glucose-rich liquid fractions obtained after pretreatment and enzymatic hydrolysis were used as a substrate for ethanol fermentation to achieve total utilization of rice husk biomass *** conclusion,the lignin-rich biomass fraction holds promise as a suitable material for chitosan-LCNF film and has the potential to increase the economic feasibility of the biomaterial industry.

关键词： Rice husk Lignocellulose nanofiber Lignin-based material Chitosan film Upcycling

An Experimental Study on the Behavior of Square Concrete-Filled High Strength Steel Tube Columns

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Journal of Iron and Steel Research International 2011年第S1期18卷 878-882页

作者： Hyung-suk jung Chang-sik Choi Department of sustainable architectural engineering Hanyang UniversitySeoulKorea Department of architectural engineering Hanyang UniversitySeoulKorea

The paper presents an experimental study on the behavior of square concrete-filled high strength steel tube columns until *** specimens were tested to investigate the effect of high strength steel and plain strength concrete on the load carrying capacity of the square concrete-filled steel tube *** effect of the concrete which filled in the steel tube was also ***,the effect of high strength steel and the presence of concrete were also *** main parameters in the tests were:(1) the ultimate strength of steel (800 Mpa),(2) the presence of concrete in steel tube (hollow steel tube and concrete-filled steel tube),and (3) slender *** main objectives of these tests were three-step:(1) to describe a series of tests on composite columns,(2) to analyze the influence of several parameters,and (3) to compare the accuracy of the predictions by using the specifications in the code (AISC-LRFD,EC4 and AIJ etc.) for the design of high-strength composite *** results indicate that the ultimate strength of steel and presence of concrete had significant influence on both the axial compressive load capacity and the ductile of the square steel tube.

关键词： square concrete-filled steel tubes high strength steel axial compression

Surgical Repair of Ventricular Septal Defect in Neonates: Indications and Outcomes

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Congenital Heart Disease 2024年第1期19卷 69-83页

作者： Jae Hong Lee Sungkyu Cho Jae Gun Kwak Hye Won Kwon Woong-Han Kim Mi Kyoung Song Sang-Yun Lee Gi Beom Kim Eun jung Bae Department of Thoracic and Cardiovascular Surgery Research Institute for Convergence of Biomedical Science and TechnologyPusan National University Yangsan HospitalYangsanKorea Department of Thoracic and Cardiovascular Surgery Seoul National University Children’s HospitalSeoulKorea Department of Pediatrics Seoul National University Children’s HospitalSeoulKorea

Background:The optimal surgical timing and clinical outcomes of ventricular septal defect(VSD)closure in neo-nates remain *** aimed to evaluate the clinical outcomes of VSD closure in neonates(age≤30 days).Methods:We retrospectively reviewed 50 consecutive neonates who underwent VSD closure for isolated VSDs between August 2003 and June *** for the procedure included congestive heart failure/failure to thrive and pulmonary *** adverse events(MAEs)were deﬁned as the composite of all-cause mortality,reoperation,persistent atrioventricular block,and signiﬁcant(≥grade 2)valvular ***:The median age and body weight at operation were 26.0 days(interquartile range[IQR],18.8–28.3)and 3.7 kg(IQR,3.3–4.2),*** median follow-up duration was 110.4 months(IQR,56.8–165.0).Seven patients required preoperative respiratory support,andﬁve had signiﬁcant(≥grade 2)preoperative valvular *** early mortality occurred due to irreversible cardiogenic shock;no late mortality was *** reopera-tion was due to hemodynamically signiﬁcant residual VSD at 103.8 months *** overall survival,freedom from reoperation,and freedom from MAE at 15-years were 98.0%,96.3%,and 94.4%,***-operative mechanical ventilation was associated with a longer duration of postoperative mechanical ventilation(p<0.001)and a longer length of intensive care unit stay(p<0.001).Conclusions:VSD closure with favorable outcomes without morbidities is feasible even in ***,neonates requiring preoperative respiratory support may require careful postoperative management considering the long-term postoperative ***,surgical VSD closure might be indicated earlier in neonates with respiratory compromise.

关键词： Ventricular septal defect neonate early surgery neonatal surgery

Varifocal occlusion in an optical see-through near-eye display with a single phase-only liquid crystal on silicon

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Photonics Research 2024年第4期12卷 833-853页

作者： WOONGSEOB HAN JAE-WON LEE jung-YEOP SHIN MYEONG-HO CHOI HAK-RIN KIM JAE-HYEUNG PARK Department of Electrical and Computer Engineering Inha University100 Inha-roMichuhol-guIncheon 22212Republic of Korea School of Electronic and Electrical Engineering Kyungpook National University80 Daehak-roBuk-guDaegu 41566Republic of Korea School of Electronics Engineering Kyungpook National University80 Daehak-roBuk-guDaegu 41566Republic of Korea Department of Information and Communication Engineering Inha University100 Inha-roMichuhol-guIncheon 22212Republic of Korea

We propose a near-eye display optics system that supports three-dimensional mutual *** exploiting the polarization-control properties of a phase-only liquid crystal on silicon (LCoS),we achieve real see-through scene masking as well as virtual digital scene imaging using a single *** depth control of the real scene mask and virtual digital image is also achieved by using a focus tunable lens (FTL) pair of opposite *** proposed configuration using a single LCoS and opposite curvature FTL pair enables the self-alignment of the mask and image at an arbitrary depth without distorting the see-through view of the real *** verified the feasibility of the proposed optics using two optical benchtop setups:one with two off-the-shelf FTLs for continuous depth control,and the other with a single Pancharatnam–Berry phase-type FTL for the improved form factor.

关键词： optics crystal phase

Altered physiology of mesenchymal stem cells in the pathogenesis of adolescent idiopathic scoliosis

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World Journal of Clinical Cases 2020年第11期8卷 2102-2110页

作者： Dai sik Ko Yun Hak Kim Tae sik Goh jung Sub Lee Division of Vascular Surgery Department of SurgeryGachon University Gil Medical CenterIncheoz 21565South Korea Department of Anatomy and Department of Biomedical Informatics School of MedicinePusan National UniversityYangsan 50612South Korea Department of Orthopaedic Surgery and Biomedical Research Institute Pusan National University HospitalBusan 49241South Korea

Adolescent idiopathic scoliosis is the most common spinal deformity during puberty,especially in *** is characterized by aberrant skeletal growth and generalized reduced bone density,which is associated with impaired bone mineral *** recent progress in multidisciplinary research to support various hypotheses,the pathogenesis of Adolescent idiopathic scoliosis is still not clearly *** of the hypothesis is to study the role of mesenchymal stem cells due to its involvement in the above-mentioned bone metabolic *** this review,we will summarize reported literatures on the role of mesenchymal stem cells,particularly in the pathogenesis of Adolescent idiopathic *** addition,we will describe the research on mesenchymal stem cells of Adolescent idiopathic scoliosis performed using bioinformatics tools.

关键词： Adolescent idiopathic scoliosis Mesenchymal stem cell Bioinformatics Transcriptome Proteome