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中国有色金属学会会刊：英文版 2012年第S3期22卷 596-604页

作者： dong-Yoon kim Young-Whan PARK Department of Mechanical Engineering Pukyong National University

Aluminum welding using a hybrid system with a laser and scanner welding head was performed under various welding conditions to verify the feasibility of applying an aluminum alloy to a car *** experimental material was 5J32 aluminum alloy,and the laser power,welding speed,and laser incidence angle were used as the control *** weld bead shape and the tensile shear strength were evaluated in order to understand the aluminum lap joint weld *** of variance (ANOVA) was conducted to identify the effect of the process variables on the tensile shear *** strength estimation models using three different regression models were also *** input variables were the laser power,welding speed,and laser incidence angle,and the output was the tensile shear *** the models,the second-order polynomial estimation model had the best estimation performance,and the average error rate of this model was 0.058.

关键词： laser welding scanner remote welding 5J32 aluminum alloy regression model

EXPLICIT BOUNDS OF EIGENVALUES FOR STIFFNESS MATRICES BY QUADRATIC HIERARCHICAL BASIS METHOD)

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Journal of Computational Mathematics 2003年第2期21卷 113-124页

作者： Sang dong kim Byeong Chun SHIN Department of Mathematics Kyungpook National UniversityTaegu 702-701KoreaDepartment of MathematicsChonnam National UniversityGwangju 500-757Korea

The bounds for the eigenvalues of the stiffness matrices in the finite element discretization corresponding to Lu := - u' with zero boundary conditions by quadratic hierarchical basis are shown explicitly. The condition number of the resulting system behaves like O(1/h) where h is the mesh size. We also analyze a main diagonal preconditioner of the stiffness matrix which reduces the condition number of the preconditioned system to O(1).

关键词： hierarchical basis multilevel

High-efficiency technique based on dielectrophoresis for assembling metal,semiconductor,and polymer nanorods

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第5期12卷 368-373页

作者： Heng YUAN Kyu-jin kim won-seok KANG Byoung-ho KANG Se-hyuk YEOM Jae-ho kim Shin-won KANG School of Electrical Engineering and Computer Science Kyungpook National University 1370 Sankyuk-dong Bukgu Daegu 702-701 Korea) Department of Molecular Science and Technology Ajou University San s.Woncheon-dongYeongtong-guSuwon 443-749Korea School of Electronic Engineering College oflT Engineering Kyungpook National University 13 70 Sankyuk-dong Bukgu Daegu 702-701 Korea

This paper presents a high-efficiency technique based on dielectrophoresis (DEP) for assembling metal, semiconductor, and polymer nanorods, which are synthesized by electrochemical deposition (ECD). The assembly patterns of these nanorods (width: 20 nm; length: 7 μm) were designed using a finite element method (FEM) simulation tool. Further, these nanorods were used in our experiment after their assembly patterns were fabricated. The assembly yield was found to be approximately 70% at an AC voltage of 30 Vp-p and at frequencies of 20 and 30 kHz, and the DC voltage prevented the random alignment of the nanorods at the edge of the assembly pattern. Moreover, the above-mentioned nanorods, which had different permittivities, were found to have similar assembly yields. The proposed method can be improved and applied to nanostructure device fabrication.

关键词： Nanorod Assembly Dielectrophoresis (DEP) Finite element method (FEM) Electrochemical deposition (ECD) method

Primary needle-knife fistulotomy for preventing post-endoscopic retrograde cholangiopancreatography pancreatitis:Importance of the endoscopist’s expertise level

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World Journal of Clinical Cases 2021年第17期9卷 4166-4177页

作者： Sung Yong Han dong Hoon Baek dong Uk kim Chang Joon Park Young Joo Park Moon won Lee Geun Am Song Division of Gastroenterology and Hepatology Internal Medicine and Biomedical Research InstitutePusan National University HospitalBusan 49241South Korea

BACKGROUND Needle-knife fistulotomy(NKF)is used as a rescue technique for difficult ***,the data are limited regarding the use of NKF for primary biliary cannulation,especially when performed by *** To assess the effectiveness and safety of primary NKF for biliary cannulation,and the role of the endoscopist’s expertise level(beginner vs expert).METHODS We retrospectively evaluated the records of 542 patients with naïve prominent bulging papilla and no history of pancreatitis,who underwent bile duct cannulation at a tertiary referral *** patients were categorized according to the endoscopist’s expertise level and the technique used for bile duct *** assessed the rates of successful cannulation and adverse *** The baseline characteristics did not differ between the experienced and lessexperienced *** incidence rate of post-endoscopic retrograde cholangiopancreatography(ERCP)pancreatitis(PEP)was significantly affected by the endoscopist’s expertise level in patients who received conventional cannulation with sphincterotomy(8.9%vs 3.4%for beginner vs expert,P=0.039),but not in those who received *** the multivariable analysis,a lower expertise level of the biliary endoscopist(P=0.037)and longer total procedure time(P=0.026)were significant risk factor of PEP in patients who received conventional cannulation with sphincterotomy but only total procedure time(P=0.004)was significant risk factor of PEP in those who received *** Primary NKF was effective and safe in patients with prominent and bulging ampulla,even when performed by less-experienced *** need to confirm which level of endoscopist’s experience is needed for primary NKF through prospective randomized study.

关键词： Needle-knife fistulotomy Primary biliary cannulation Endoscopic retrograde cholangiopancreatography Expertise levels Pancreatitis

Tailored eradication strategy vs concomitant therapy for Helicobacter pylori eradication treatment in Korean patients

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World Journal of Gastroenterology 2021年第31期27卷 5247-5258页

作者： Youn I Choi Jun-won Chung Kyoung Oh kim Kwang An Kwon Yoon Jae kim Jung Ho kim Ja Young Seo dong Kyun Park Division of Internal Medicine Department of GastroenterologyGachon University College of MedicineGil Medical CenterInchoen 21565South Korea Department of Laboratory Medicine Gil Medical CenterGachon UniversityInchoen 21565South Korea Health IT Research Center Gachon University Gil HospitalIncheon 21565South Korea

BACKGROUND Antibiotic resistance to Helicobacter pylori(***)infection,which ultimately results in eradication failure,has been an emerging issue in the clinical ***,to overcome this problem,an antibiotic sensitivity-based tailored therapy(TT)for *** infection has received *** To investigate the efficacy and safety profiles of TT for *** infection treatment compared to a non-bismuth quadruple therapy,concomitant therapy(CT)*** We included patients(>18 years)with an *** infection and without a history of Helicobacter eradication who visited the Gil Medical Center between March 2016 and October *** being randomly assigned to either the TT or CT treatment group in 1 to 1 manner,patient compliance,eradication success rate(ESR),and patient-reported side effects profiles were assessed and compared between the two *** infection was diagnosed using a rapid urease test,Giemsa stain,or dual priming oligonucleotide polymerase chain reaction(DPO-PCR).Tailored eradication strategy based through the presence of a 23S ribosomal RNA point *** the TT group,a DPO-PCR test,which detected A2142G and/or A2143G point mutations,and a clarithromycin resistance test were *** in the clarithromycin-resistant group were treated with a bismuth-containing quadruple combination therapy,while those with sensitive results were treated with the standard triple *** Of the 217 patients with a treatment naive *** infection,110 patients[mean age:58.66±13.03,men,n=55(50%)]were treated with TT,and 107 patients[mean age:56.67±10.88,men,n=52(48.60%)]were treated with *** compliance(TT vs CT,100%vs 98.13%,P=0.30),and follow-up loss rates(8.18%vs 9.35%,P=0.95)were not significantly different between the *** ESR after treatment was also not statistically different between the groups(TT vs CT,82.73%vs 82.24%,P=0.95).However,the treatment-related and patient-reported side effects were signifi

关键词： Helicobacter pylori Eradication Tailored therapy Conco-mitant therapy regimen

Improved Cycle Properties of FeS_2 Cathode Material with Metallic Additives

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材料科学与工程学报 2007年第6期25卷 910-913页

作者： Jae-won Choi Jae-Kwang kim Gouri Cheruvally Jou-Hyeon Ahn Ki-won kim Hyo-Jun Ahn dong-Kyu Park Department of Chemical & Biological Engineering and Engineering Research Institute Gyeongsang National University900 Gajwa-dongJinju660-701Korea School of Nano and Advanced Materials Engineering and Engineering Research Institute Gyeongsang National University900 Gajwa-dongJinju660-701Korea Kaya Advanced Material Art Inc. Baekrok-Ri 1010-1Yangsan 626-862Korea

Iron disulfide(FeS_2)cathode active material was prepared from iron and sulfur at room temperature by high energy mechanical *** FeS_2 composites containing Co or Ni transition metal powders as additives were also prepared by the same *** cells with these FeS_2 cathodes were studied for charge-discharge properties at room temperature using 0.5M LiTFSI in tetra(ethylene glycol)dimethyl ether(TEGDME)*** voltammetry showed two anodic oxidation peaks at 1.8 and 2.5V and two cathodic reduction peaks at 2.0 and 1.3 V for FeS_2 with metal *** addition of 5wt% Co and 3wt% Ni resulted in an enhancement of the first discharge capacity giving 571 and 844mAh/g respectively at *** cycle performance was also enhanced remarkably by the addition of these electrically conductive transition metals in the active ***_2 with 5wt% Co exhibited a stable cycle performance delivering a reversible capacity of 338mAh/g(37.8% of theoretical capacity)after 20 cycles.

关键词：阴极材料二硫化铁锂离子电池循环性能

Investigation into charge carrier dynamics in organic light-emitting diodes

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Nano Research Energy 2024年第2期3卷 39-46页

作者： dong-Guang Zheng Hyeon-dong Lee Gyeong won Lee dong-Soo Shin Jeongwon kim Jong-In Shim Zhiqun Lin Tae-Woo Lee dong Ha kim Information Engineering College Hangzhou Dianzi UniversityHangzhou 311305China Department of Materials Science and Engineering Seoul National University1 Gwanak-roGwanak-guSeoul 08826Republic of Korea Department of Photonics and Nanoelectronics Hanyang University ERICA55 Hanyangdeahak-roSangnok-guAnsanGyeonggi 15588Republic of Korea Department of Chemistry and Nanoscience Ewha Womans University52Ewhayeodae-gilSeodaemun-guSeoul 03760Republic of Korea Department of Chemical and Biomolecular Engineering National University of Singapore4 Engineering Drive 4Singapore 117585Singapore School of Chemical and Biological Engineering Institute of Engineering ResearchResearch Institute of Advanced MaterialsSoft FoundrySeoul National University1 Gwanak-roGwanak-guSeoul 08826Republic of Korea Basic Sciences Research Institute(Priority Research Institute) Ewha Womans UniversitySeoul 03760Republic of Korea Nanobio∙Energy Materials Center(National Research Facilities and Equipment Center) Ewha Womans UniversitySeoul 03760Republic of Korea

Organic light-emitting diodes(OLEDs)have demonstrated remarkable advancements in both device lifetime and luminous ***,insufficient operation lifetime due to device degradation remains a major hurdle,especially for brighter *** the degradation mechanisms of OLEDs due to the degradation of functional materials and the formation of defects in device architectures continues to be a significant ***,we evaluate the degradation characteristics by scrutinizing the electrical and optical properties,as well as analyzing the charge carrier dynamics in pristine and aged states of phosphorescent OLEDs(PhOLEDs).We show that degradation mechanisms in PhOLEDs can be elucidated in terms of the ideality factors of current and luminance in pristine and aged device *** consistent shifts in distinct ideality factors across various states points out that the device degradation is attributed to the deterioration of the guest material,***-light-emitting phosphorescent ***,the incongruity in ideality factor changes between the two states indicates that the degradation results from the deterioration of non-light-emitting *** characterization experiments provide further evidence that this degradation is primarily attributed to the deterioration of CBP-host *** thorough understanding of degradation mechanisms established in this study can contribute to realizing the highly reliable PhOLEDs with a long lifetime.

关键词： organic light-emitting diodes ideality factor carrier transport processes degradation mechanism

Complete characterization of ultrafast optical fields by phase-preserving nonlinear autocorrelation

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Light(Science & Applications) 2022年第10期11卷 2451-2462页

作者： Alexander Gliserin Soo Hoon Chew Seungchul kim dong Eon kim Department of Optics and Mechatronics Engineering College of Nanoscience and NanotechnologyPusan National University2 Busandaehak-ro 63beon-gilBusan 46241South Korea Department of Cogno Mechatronics Engineering College of Nanoscience and NanotechnologyPusan National University2 Busandaehak-ro 63beon-gilBusan 46241South Korea Max Planck Center for Attosecond Science Max Planck POSTECH/Korea Research Initiative77 Cheongam-roPohang 37673South Korea Department of Physics Center for Attosecond Science and TechnologyPohang University of Science and Technology77 Cheongam-roPohang 37673South Korea

Nonlinear autocorrelation was one of the earliest and simplest tools for obtaining partial temporal information about an ultrashort optical pulse by gating it with ***,since the spectral phase is lost in a conventional autocorrelation measurement,it is insufficient for a full characterization of an ultrafast electric field,requiring additional spectral information for phase ***,we show that introducing an intensity asymmetry into a conventional nonlinear interferometric autocorrelation preserves some spectral phase information within the autocorrelation signal,which enables the full reconstruction of the original electric field,including the direction of time,using only a spectrally integrating *** call this technique Phase-Enabled Nonlinear Gating with Unbalanced Intensity(PENGUIN).It can be applied to almost any existing nonlinear interferometric autocorrelator,making it capable of complete optical field characterization and thus providing an inexpensive and less complex alternative to methods relying on spectral measurements,such as frequency-resolved optical gating(FROG)or spectral phase interferometry for direct electric-field reconstruction(SPIDER).More importantly,PENGUIN allows the precise characterization of ultrafast fields in non-radiative(e.g.,plasmonic)nonlinear optical interactions where spectral information is *** demonstrate this novel technique through simulations and experimentally by measuring the electric field of~6-fs laser pulses from a Ti:sapphire *** results are validated by comparison with the well-established FROG method.

关键词： autocorrelation nonlinear characterization

Synthesis and Gas Sensing of TiO_2 Ultrafine Powders by Precipitating

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稀有金属材料与工程 2006年第A3期35卷 163-164页

作者： Min-Hyun Seo Bong-Ho Lee Jong-won kim Gi-Hong Rue Duk-dong Lee Jeung-Soo Huh Department of Sensor and Display Engineering Kyungpook National UniversitySangyuk-DongBukguDaegu 1370Korea Department of Materials Science and Metallurgy Kyungpook National UniversitySangyuk-DongBukguDaegu 1370Korea Department of Nano-science and Technology Kyungpook National UniversitySangyuk-DongBukguDaegu 1370Korea School of Electronic Engineering Kyungpook National UniversitySangyuk-DongBukguDaegu 1370Korea Department of Sensor and Display Engineering Kyungpook National UniversitySangyuk-DongBukguDaegu 1370Korea.Department of Nano-science and TechnologyKyungpook National UniversitySangyuk-DongBukguDaegu 1370Korea

We investigated the gas sensing characteristics of rutile and anatase TiO_2 nano-particle sensors for chemical warfare ***_2 nano-powders with rutile and anatase structure were fabricated by controlling pH value without heat treatment *** mean particle size of TiO_2 powders were below 10 ***-prepared TiO_2 powders have several advantages of nano particle size and high surface area and could be a prominent candidate for ***_2 sensors were examined with DMMP for chemical warfare agents detection.

关键词： TiO2 chemical warfare agents sensor nano-sensor pH

Atomic layer deposition for nanoscale oxide semiconductor thin film transistors:review and outlook

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International Journal of Extreme Manufacturing 2023年第1期5卷 153-180页

作者： Hye-Mi kim dong-Gyu kim Yoon-Seo kim Minseok kim Jin-Seong Park Division of Materials Science and Engineering Hanyang University222 Wangsimni-roSeongdong-guSeoul 04763Republic of Korea

Since the first report of amorphous In–Ga–Zn–O based thin film transistors,interest in oxide semiconductors has *** offer high mobility,low off-current,low process temperature,and wide flexibility for compositions and ***,depositing oxide semiconductors using conventional processes like physical vapor deposition leads to problematic issues,especially for high-resolution displays and highly integrated memory *** approaches have limited process flexibility and poor conformality on structured *** layer deposition(ALD)is an advanced technique which can provide conformal,thickness-controlled,and high-quality thin film ***,studies on ALD based oxide semiconductors have dramatically increased *** so,the relationships between the film properties of ALD-oxide semiconductors and the main variables associated with deposition are still poorly understood,as are many issues related to *** this review,to introduce ALD-oxide semiconductors,we provide:(a)a brief summary of the history and importance of ALD-based oxide semiconductors in industry,(b)a discussion of the benefits of ALD for oxide semiconductor deposition(in-situ composition control in vertical distribution/vertical structure engineering/chemical reaction and film properties/insulator and interface engineering),and(c)an explanation of the challenging issues of scaling oxide semiconductors and ALD for industrial *** review provides valuable perspectives for researchers who have interest in semiconductor materials and electronic device applications,and the reasons ALD is important to applications of oxide semiconductors.

关键词： atomic layer deposition(ALD) oxide semiconductor thin film transistor(TFT)