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Journal of Materials science & Technology 2022年第10期105卷 45-56页

作者： Keekeun Kim Damhyun Kim Kibum park Junghan Yun Chang-sung seok s.h.ol of Mechanical Engineering Sungkyunkwan UniversitySuwonGyeonggi 440-746Korea

The lifespan of plasma-sprayed thermal barrier coating(TBC)systems is difficult to predict owing to the variety of microstructures and deterioration *** this study,we developed a novel TBC damage model to reflect deterioration histories;thus,it can be applied to various *** to TBCs is classifed into oxidation and mechanical damage;therefore,a detailed deterioration history can be *** addition,by introducing a virtual s–N diagram,a life prediction model that can be applied to TBCs with various microstructures was *** used the proposed damage and life prediction models in isothermal aging and thermal cycle tests with different aging *** predicted lifespan of TBCs by using the proposed models was within 95%of the results obtained by performing actual tests in the temperature range of 1150–1350℃.

关键词： Thermal barrier coatings Damage model Temperature history Thermal fatigue Life prediction model

study of the Interface between steel Insert and Aluminum Casting in EPC

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Journal of Materials science & Technology 2008年第1期24卷 60-64页

作者： K.h.Choe K.s.park B.h.Kang G.s.Cho K.Y.Kim K.W.Lee M.h.Kim A.Ikenaga s.Koroyasu Advanced Material Processing Team Korea Institute of Industrial Technology IncheonKorea Department of Materials Engineering Korea University of Technology and Education ChoongnamKorea Department of Materials science and Engineering Inha University IncheonKorea Department of Metallurgy and Materials science Graduate s.h.ol of Engineering Osaka Prefecture UniversityOsakaJapan Department of Mechanical and Precision systems Teiko University UtsunomiyaJapan

The effective surface treatment method for steel insert composited with Al base metal by expendable pattern casting （EPC） process and the bonding interface between steel insert and Al base metal were *** was found that Zn plating on steel insert was effective on improving the bonding property between steel insert and Al base metal in EPC *** is thought to promote the formation of diffusion *** almost none content of Zn was observed in the boundary which had been plated on the steel insert.A diffusion layer consisting of Al,si and Fe was formed at the insert/alloy interface and its.h.rdness was.h.gher than the steel insert as matter of course Al base *** layer turned out to be intermetallic compounds of Al-si-Fe *** pouring temperature promoted the diffusion of Fe into Al alloy,so Fe content in intermetallic layers increased at higher pouring *** layer nearest to steel disappeared due to applied pressure.

关键词： Expendable pattern casting Insert casting Intermetallic compound Al-si-Fesystem

Near-sensor computing-assisted simultaneous viral antigen and antibody detection via integrated label-free biosensors with microfluidics

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InfoMat 2023年第10期5卷 80-95页

作者： Byungjoon Bae Yongmin Baek Jeongyong Yang heesung Lee Charana s.s.sonnadara sangeun Jung Minseong park Doeon Lee s.h.an Kim Gaurav Giri s.h.l shah Geonwook Yoo William APetri Kyusang Lee Department of Electrical and Computer Engineering University of VirginiaCharlottesvilleVirginiaUSA s.h.ol of Electronic Engineering Soongsil UniversitySeoulRepublic of Korea Department of Electrical and Computer Engineering University of MarylandCollege ParkMarylandUSA Department of Chemical Engineering University of VirginiaCharlottesvilleVirginiaUSA Division of Infectious Diseases and International health Department of MedicineSchool of MedicineUniversity of VirginiaCharlottesvilleVirginiaUSA Department of Material science and Engineering University of VirginiaCharlottesvilleVirginiaUSA Department of Intelligent semiconductors Soongsil UniversitySeoulRepublic of Korea

Precise diagnosis and immunity to viruses,such as severe acute respiratory syndrome coronavirus 2(sARs-CoV-2)and Middle East respiratory syndrome coronavirus(MERs-CoV)is achieved by the detection of the viral antigens and/or corresponding antibodies,***,a widely used antigen detection methods,such as polymerase chain reaction(PCR),are complex,expensive,and time-consuming Furthermore,the antibody test that detects an asymptomatic infection and immunity is usually performed separately and exhibits relatively low *** achieve a simplified,rapid,and accurate diagnosis,we have demonstrated an indium gallium zinc oxide(IGZO)-based biosensor field-effect transistor(bio-FET)that can simultaneously detect spike proteins and antibodies with a limit of detection(LOD)of 1 pg mL–1 and 200 ng mL–1,respectively using a single assay in less than 20 min by integrat-ing microfluidic channels and artificial neural networks(ANNs).The near-sensor ANN-aided classification provides.h.gh diagnosis accuracy(>93%)with significantly reduced processing time(0.62%)and energy consumption(5.64%)compared to the software-based *** believe that the development of rapid and accurate diagnosis system for the viral antigens and antibodies detec-tion will play a crucial role in preventing global viral outbreaks.

关键词： artificial intelligence biosensor edge-computing integration microfluidic

Current recommendations of managing hBV infection in preconception or pregnancy

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Frontiers of Medicine 2014年第2期8卷 158-165页

作者： James s. park Calvin Pan Division of Gastroenterology Department of Medicine NYU Langone Medical Center NYU School of Medicine New York 10016 USA

hepatitis B remains a leading cause of cirrhosis, hepatocellular carcinoma and liver transplantation worldwide. Management of chronic hepatitis B during pregnancy is challenging. Transmission of hepatitis B to infants still occurs perinataily although immunoprophylaxis is widely available for infants born to mothers with chronic hepatitis B infection. The emerging data suggest that initiation of antiviral therapy in the beginning of the third trimester in highly viremic mothers can prevent immunoprophylaxis failure in their infants. The available drug safety data show that lamivudine, telbivudine and tenofovir are generally safe to be used during the pregnancy. In order to minimize the fetal exposure to the antiviral medication, antiviral therapy during the pregnancy should be limited to a selected group of patients with cirrhosis, high hepatitis B viral load, or prior history immunoprophylaxis failure. An elective Caesarean section may reduce the risk of perinatal transmission. For those females planning for pregnancy or in early stage of pregnancy, communication and follow-up among obstetrician, gastroenterologist, and primary care physician are important. In this article, we will review the features of hepatitis B infection before, during and after the pregnancy; the risk factors that increase mother-tochild transmission; safety data on antiviral drug use during pregnancy; and the potential role of Caesarean section in selected cases.

关键词： antiviral therapy Caesarean section cirrhosis hepatitis B irnmunoprophylaxis mother-to-child transmission pregnancy prevention

hot Data Identification with Multiple Bloom Filters： Block-Level Decision vs I/O Request-Level Decision

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Journal of Computer science & Technology 2018年第1期33卷 79-97页

作者： Dongchul park Weiping he h. C. Du Division of Computer and Electronic systems Engineering Hankuk University of Foreign Studies Gyeonggi-do 17035 Korea Intel Corporation Hillsboro OR 97124 U.S.A. Dell storage Eden Prairie MN 55344 U.S.A. Department of Computer science and Engineering University of Minnesota-Twin Cities Minneapolis MN 55455 U.S.A.

hot data identification is crucial for many applications though few investigations.h.ve examined the subject. All existing studies focus almost exclusively on frequency. however, effectively identifying hot data requires equally considering recency and frequency. Moreover, previous studies make hot data decisions at the data block level. such a fine-grained decision fits particularly well for flash-based storage because its random access achieves performance comparable with its sequential access. however, hard disk drives （hDDs） have a significant performance disparity between sequential and random access. Therefore, unlike flash-based storage, exploiting asymmetric hDD access performance requires making a coarse-grained decision. This paper proposes a novel hot data identification s.h.me adopting multiple bloom filters to efficiently characterize recency as well as frequency. Consequently, it not only consumes 50% less memory and up to 58% less computational overhead, but also lowers false identification rates up to 65% compared with a state-of-the-art s.h.me. Moreover, we apply the s.h.me to a next generation hDD technology, i.e., shingled Magnetic Recording （sMR）, to verify its effectiveness. For this, we design a new hot data identification based sMR drive with a coarse-grained decision. The experiments demonstrate the importance and benefits of accurate hot data identification, thereby improving the proposed sMR drive performance by up to 42%.

关键词： hot data bloom filter shingled magnetic recording (sMR)

The role of histone modifications:from neurodevelopment to neurodiseases

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signal Transduction and Targeted Therapy 2022年第8期7卷 2710-2732页

作者： Jisu park Kyubin Lee Kyunghwan Kim sun-Ju Yi Department of Biological sciences and Biotechnology Chungbuk National UniversityCheongjuChungbukRepublic of Korea

Epigenetic regulatory mechanisms,including DNA methylation,histone modification,chromatin remodeling,and microRNA expression,play critical roles in cell differentiation and organ development through spatial and temporal gene *** is a sophisticated and complex process by which neural stem cells differentiate into specialized brain cell types at specific times and regions of the brain.A growing body of evidence suggests that epigenetic mechanisms,such as.h.stone modifications,allow the fine-tuning and coordination of spatiotemporal gene expressions during *** histone modifications contribute to the development of neurodegenerative and neuropsychiatric ***,recent progress in understanding histone modifications in regulating embryonic and adult neurogenesis is comprehensively *** histone modifications implicated in neurodegenerative and neuropsychiatric diseases are also covered,and future directions in this area are provided.

关键词： diseases specialized modification

scale-invariant machine-learning model accelerates the discovery of quaternary chalcogenides with ultralow lattice thermal conductivity

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npj Computational Materials 2022年第1期8卷 455-466页

作者： Koushik Pal Cheol Woo park Yi Xia Jiahong shen Chris Wolverton Department of Materials science and Engineering Northwestern UniversityEvanstonIL60208USA

We design an advanced machine-learning(ML)model based on crystal graph convolutional neural network that is insensitive to volumes(i.e.,scale)of the input crystal structures to discover novel quaternary chalcogenides,AMM′Q3(A/M/M'=alkali,alkaline earth,post-transition metals,lanthanides,and Q=chalcogens).These compounds are shown to possess ultralow lattice thermal conductivity(κ_(l)),a desired requirement for thermal-barrier coatings and *** screening the thermodynamic stability of~1 million compounds using the ML model iteratively and performing density-functional theory(DFT)calculations for a small fraction of compounds,we discover 99 compounds that are validated to be stable in *** several DFT-stable compounds,we calculate theirκl using Peierls–Boltzmann transport equation,which reveals ultralowκ_(l)(heir soft elasticity and strong phonon *** work demonstrates the high efficiency of scale-invariant ML model in predicting novel compounds and presents experimental-research opportunities with these new compounds.

关键词： ultralow thermal invariant

Effects of Weaving Laser on Weld Microstructure and Crack for Al 6k21-T4 Alloy

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Journal of Materials science & Technology 2011年第1期27卷 93-96页

作者： B.h.Kim N.h.Kang W.T.Oh C.h.Kim J.h.Kim Y.s.Kim Y.h.park Department of Materials science and Engineering Pusan National UniversitySan30Jangjeon-dongGeumjeong-guBusan 609-735Korea Department of Materials and Components Engineering Dong-Eui UniversityBusan 614-714Korea Advanced Joining Technology Team KITECH7-47Songdo-dongYeonsu-guIncheon 406-840Korea Division for Dongnam Area Technology service KITECHJisa-dongGanseo-guBusan 618-230Korea

For Al 6k21-T4 overlap weld joint,the shear-tensile strength by using the weaving laser was improved as compared to the case of linear *** the specimen of low strength,the porosity was distributed continuously along the intersection between the plates and fusion ***,for the optimized welding condition,large oval-shaped porosities were located only in the advancing track of the concave ***,the continuity of cracks and porosities played a key role to determine the ***,the weaving width was also the important parameter to control the ***,the concave part had more significant hot and cold cracking in the weld and heat-affected zone（hAZ）,respectively,than the convex part.

关键词： Weaving laser Weld microstructure Void Al alloy

Pseudo NLP Joint spam Classification Technique for Big Data Cluster

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Computers, Materials & Continua 2022年第4期71卷 517-535页

作者： Woohyun park Nawab Muhammad Faseeh Qureshi Dong Ryeol shin Department of Electrical and Computer Engineering Sungkyunkwan UniversitySuwon16419Korea Department of Computer Education Sungkyunkwan UniversitySeoul03063Korea

spam mail classification considered complex and error-prone task in the distributed computing *** are various available spam mail classification approaches such as the naive Bayesian classifier,logistic regression and support vector machine and decision tree,recursive neural network,and long short-term memory ***,they do not consider the document when analyzing spam mail *** approaches use the bagof-words method,which analyzes a large amount of text data and classifies features with the help of term frequency-inverse document *** there are many words in a document,these approaches consume a massive amount of resources and become infeasible when performing classification on multiple associated mail documents ***,spam mail is not classified fully,and these approaches remain with ***,we propose a term frequency topic inverse document frequency model that considers the meaning of text data in a larger semantic unit by applying weights based on the document’s ***,the proposed approach reduces the scarcity problem through a frequency topic-inverse document frequency in singular value decomposition *** proposed approach also reduces the dimensionality,which ultimately increases the strength of document *** evaluations show that the proposed approach classifies spam mail documents with higher accuracy using individual document-independent processing *** evaluations show that the proposed approach performs better than the logistic regression model in the distributed computing environment,with higher document word frequencies of 97.05%,99.17%and 96.59%.

关键词： NLP big data machine learning TFT-IDF spam mail

Difference in the hot Compressive Behavior and Processing Maps between the As-cast and homogenized Al-Zn-Mg-Cu(7075) Alloys

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Journal of Materials science & Technology 2016年第7期32卷 660-670页

作者： s.Y. park W.J. Kim Department of Materials science and Engineering Hongik University 72-1 Sangsu-dong Mapo-gu Seoul 121-791 Republic of Korea Advanced Fusion Process R&D Group Korea Institute of Industrial Technology 994-32 Dongchun-dong Yeonsu-gu Incheon 406-130 Republic of Korea

The deformation mechanisms and processing maps of the as-cast Al-Zn-Mg-Cu （？0？5） aluminum （AI） alloy were studied and compared with those of the homogenized 7075 Al alloy in the temperature range of 573-723 K and in the strain rate range of 10 3-10 s-1 to explore a possibility for directly using the as- cast 7075 Al alloy as a billet for hot working. The as-cast and homogenized 7075 A1 alloys.h.d similar grain sizes and showed similar high-temperature deformation behaviors. The as-cast 7075 Al alloy, however, exhibited higher power efficiencies and smaller unstable flow regions compared to the homogenized 7075 AI alloy because of the presence of secondary phases （MgZn2） segregated at the dendritic interfaces in the as-cast microstructure, which were formed during non-equilibrium solidification. These segregated phases provided nucleation sites for dynamic recovery or continuous dynamic recrystallization, and as a result a fine and more homogeneous （sub）grain structure could be obtained from the as-cast micro- structure compared to the homogenized microstructure. The current work suggested the possibility and advantage of using as-cast microstructures for hot working of aluminum alloys with high content of solutes.

关键词： Al-based alloysProcessing maphot compressionAs-cast microstructuresegregationRecrystallization