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Dynamic modeling and analysis of vortex filament motion using a novel curve-fitting method

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Chinese Journal of Aeronautics 2016年第1期29卷 53-65页

作者： chang-Joo Kim Soo Hyung Park Sang Kyung sung sung-Nam Jung Department of Aerospace Information Engineering Konkuk UniversitySeoul 05029Republic of Korea

Applications of a novel curve-fitting technique are presented to efficiently predict the motion of the vortex filament, which is trailed from a rigid body such as wings and rotors. The gov- erning equations of the motion, when a Lagrangian approach with the present curve-fitting method is applied, can be transformed into an easily solvable form of the system of nonlinear ordinary dif- ferential equations. The applicability of Bezier curves, B-spline, and Lagrange interpolating polyno- mials is investigated. Local Lagrange interpolating polynomials with a shift operator are proposed as the best selection for applications, since it provides superior system characteristics with minimum computing time, compared to other methods. In addition, the Gauss quadrature formula with local refinement strategy has been developed for an accurate prediction of the induced velocity computed with the line integration of the Biot-Savart law. Rotary-wing problems including a vortex ring problem are analyzed to show the efficiency, accuracy, and flexibility in the applications of the pro- posed method.

关键词： Aerodynamics Biot-Savart law Curve-fitting method Free-vortex wake Rotary wing Vortex filament

Enhanced Electrical Properties in Carbon Nanotube/Poly （3-hexylthiophene） Nanocomposites Formed Through Non-Covalent Functionalization

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Nano Research 2011年第11期4卷 1129-1135页

作者： sung Hye Park sung hwan Jin Gwang Hoon Jun SeokwoO Jeon Soon Hyung Hong Department of Material Science and Engineering Korea Advanced Institutc of Science Technol0gy Daejeon 305＇701 Republic of Korea

Poly（3-hexylthiophene）（P3HT） has received much attention as a good candidate to replace inorganic semiconductors for flexible electronics due to its solution-processability. However, the low charge mobility of P3HT is an obstacle to its commercialization. To overcome this problem, we propose a new non-covalent functionalization method for carbon nanotubes （CNTs） for use in CNT/P3HT nanocomposites. By using modified pyrene molecules with hydrophobic long alkyl chains, the non-covalently functionalized CNTs can become well dispersed in hydrophobic solutions and organic semiconductor matrices. Fabrication of organic thin-film transistors （OTFTs） from the non-covalently functionalized CNT/organic semiconductor nanocomposites shows that our non-covalent functionalization method significantly reduces damage to CNTs during functionalization when compared with covalent functionalization by treatment with acids. The OTFTs show 15 times enhancement of field effect mobility （1.5 × 10^-2 cm^2/（V.s）） compared to the mobility of OTFTs made from pure P3HT. This enhancement is achieved by addition of only 0.25 wt% of CNTs to P3HT.

关键词： Carbon nanotubes conjugated polymers nanocomposites organic thin film transistors

Therapeutic effect of DA-9601 on chronic reflux gastritis induced by sodium taurocholate in rats

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World Journal of Gastroenterology 2005年第47期11卷 7430-7435页

作者： Tae Young Oh chang Yell Shin Yong sung Sohn Dong hwan Kim Byoung Ok Ahn Eun Bang Lee Cho Hyun Park Dong-A Pharmaceutical Research Institute YonginKorea Department of General Surgery Catholic University of MedicineSeoulKorea

AIM: To investigate the therapeutic effects of DA-9601 on sodium taurocholate (TCA)-induced chronic reflux gastritis in SD ***: In this study, we have investigated the therapeutic effects of DA-9601 on chronic erosive and atrophic gastritis induced by 6 mo of TCA administration (5 mmol/L in drinking water) in SD rats. RESULTS: Four weeks of DA-9601 administration (0.065%, 0.216% in rat chow), following the withdrawal of TCA treatment, resulted in a significant decrease in total length of erosions in rats in a dose-dependent manner. Furthermore, the indicators of atrophic gastritis, such as reduced mucosal thickness and reduction in the number of parietal cells, were improved by the administration of DA-9601 in a dose-related manner. DA-9601 also attenuated inflammatory cell infiltration and the proliferation of collagenous fiber in the gastric mucosa. The improvement in the reduction of the gastric mucus was observed in the rats receiving a high dose of DA-9601 (0.216%). The therapeutic effect of DA-9601 on experimental chronic erosive gastritis was superior to that of rebamipide (1.08% in rat chow). Biochemical analyses showed increased mucosal prostaglandin E2 and reduced glutathione levels by DA-9601 treatment. CONCLUSION: We suggest that DA-9601 is apromising agent for the treatment of chronic erosive and atrophic gastritis with an etiological factor of bile reflux. Increasedmucosal prostaglandin E2 and reduced glutathione by DA-9601 treatment may be therapeutic mechanisms for chronic erosive and atrophic gastritis.

关键词： DA-9601 Reflux gastritis Erosive gastritis Atrophic gastritis Sodium taurocholate

Formulation of Reduction Rate for Ultimate Compressive Strength of Stiffened Panel Induced by Opening

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China Ocean Engineering 2014年第4期28卷 557-568页

作者：于昌利 LEE Joo-sung School of Naval Architecture and Ocean Engineering Harbin Institute of Technology School of Naval Architecture and Ocean Engineering University of Ulsan

The main objective of this study is to numerically investigate the characteristics of ultimate compressive strength of stiffened panels with opening and also to fit the design-oriented formulae. For this purpose, three series of well executed experimental data on longitudinally stiffened steel plates with and without opening subjected to the uniform axial in-pane load which is carried out to study the buckling and post-buckling up to the final failure are chosen. Also, a nonlinear finite element method capable of efficiently analyzing the large elasto-plastic deflection behavior of stiffened panels is developed and used for simulation. The feasibility of the present simulation process is confirmed by a good agreement with the experimental results. More case studies are developed employing the simulation process to analyze the influence of various design variables on the reduction rate of ultimate strength of stiffened panel induced by opening. Based on the computed results, two design formulae are fitted and the accuracy of design formulae is studied. Furthermore, the viability of the design formulae for practical engineering is proved.

关键词： stiffened panel opening reduction rate non-linear analysis formulae fitting

Effect of preparation method of noble metal supported catalyts on formaldehyde oxidation at room temperature: Gas or liquid phase reduction

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Journal of Environmental Sciences 2022年第12期34卷 201-216页

作者： Younghee Jang Ye hwan Lee Hanki Eom Sang Moon Lee sung Su Kim Department of Environmental Energy Envineering Graduate School of kyonggi UniversityGyeonggi-do 16227Korea Department of Environmental Energy Engineeing Kyonggi UniversityGyonggi-do 16227Korea

Formaldehyde(HCHO) is toxic to the human body and is one of the main threats to the indoor air quality(IAQ). As such, the removal of HCHO is imperative to improving the IAQ,whereby the most useful method to effectively remove HCHO at room temperature is catalytic oxidation. This review discusses catalysts for HCHO room-temperature oxidation,which are categorized according to their preparation methods, i.e., gas-phase reduction and liquid-phase reduction methods. The HCHO oxidation performances, structural features,and reaction mechanisms of the different catalysts are discussed, and directions for future research on catalytic oxidation are reviewed.

关键词： Formaldehyde Indoor air quality Catalyst Prepared method

Outcomes of combined mitochondria and mesenchymal stem cellsderived exosome therapy in rat acute respiratory distress syndrome and sepsis

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World Journal of Stem Cells 2024年第6期16卷 690-707页

作者： Kun-Chen Lin Wen-Feng Fang Jui-Ning Yeh John Y Chiang Hsin-Ju Chiang Pei-Lin Shao Pei-Hsun sung Hon-Kan Yip Department of Anesthesiology Kaohsiung Chang Gung Memorial HospitalKaohsiung 83301TaiwanChina Division of Pulmonary and Critical Care Medicine Department of Internal MedicineKaohsiung Chang Gung Memorial HospitalChang Gung University College of MedicineKaohsiung 83301TaiwanChina Department of Cardiology The First Affiliated Hospital of Jinan UniversityGuangzhou 510630Guangdong ProvinceChina Department of Computer Science and Engineering National Sun Yat-sen UniversityKaohsiung 804201TaiwanChina Department of Healthcare Administration and Medical Informatics Kaohsiung Medical UniversityKaohsiung 80708TaiwanChina School of Medicine Chung Shan Medical UniversityTaichung 40201TaiwanChina Department of Nursing Asia UniversityTaichung 41354TaiwanChina Division of Cardiology Department of Internal MedicineKaohsiung Chang Gung Memorial Hospital and Chang Gung University College of MedicineKaohsiung 83301TaiwanChina Institute for Translational Research in Biomedicine Kaohsiung Chang Gung Memorial HospitalKaohsiung 83301TaiwanChina Center for Shockwave Medicine and Tissue Engineering Kaohsiung Chang Gung Memorial HospitalKaohsiung 83301TaiwanChina Department of Medical Research China Medical University HospitalChina Medical UniversityTaichung 40402TaiwanChina School of Medicine College of MedicineChang Gung UniversityTaoyuan 33302TaiwanChina

BACKGROUND The treatment of acute respiratory distress syndrome(ARDS)complicated by sepsis syndrome(SS)remains *** To investigate whether combined adipose-derived mesenchymal-stem-cells(ADMSCs)-derived exosome(EXAD)and exogenous mitochondria(mitoEx)protect the lung from ARDS complicated by *** In vitro study,including L2 cells treated with lipopolysaccharide(LPS)and in vivo study including male-adult-SD rats categorized into groups 1(sham-operated-control),2(ARDS-SS),3(ARDS-SS+EXAD),4(ARDS-SS+mitoEx),and 5(ARDS-SS+EXAD+mitoEx),were included in the present *** In vitro study showed an abundance of mitoEx found in recipient-L2 cells,resulting in significantly higher mitochondrial-cytochrome-C,adenosine triphosphate and relative mitochondrial DNA levels(P<0.001).The protein levels of inflammation[interleukin(IL)-1β/tumor necrosis factor(TNF)-α/nuclear factor-κB/toll-like receptor(TLR)-4/matrix-metalloproteinase(MMP)-9/oxidative-stress(NOX-1/NOX-2)/apoptosis(cleaved-caspase3/cleaved-poly(ADP-ribose)polymerase)]were significantly attenuated in lipopolysaccharide(LPS)-treated L2 cells with EXAD treatment than without EXAD treatment,whereas the protein expressions of cellular junctions[occluding/β-catenin/zonula occludens(ZO)-1/E-cadherin]exhibited an opposite pattern of inflam-mation(all P<0.001).Animals were euthanized by 72 h post-48 h-ARDS induction,and lung tissues were *** 72 h,flow cytometric analysis of bronchoalveolar lavage fluid demonstrated that the levels of inflam-matory cells(Ly6G+/CD14+/CD68+/CD11b/c+/myeloperoxidase+)and albumin were lowest in group 1,highest in group 2,and significantly higher in groups 3 and 4 than in group 5(all P<0.0001),whereas arterial oxygen-saturation(SaO2%)displayed an opposite pattern of albumin among the *** findings of lung injury/fibrosis area and inflammatory/DNA-damaged markers(CD68+/γ-H2AX)displayed an identical pattern of SaO2%among the groups(all P<0.0001).The pro

关键词： Acute respiratory distress syndrome Sepsis syndrome Exosomes Mitochondria Adipose tissue-derived mesenchymal stem cells Inflammation

Self-expandable metal stents for choledocholithiasis in Billroth II gastrectomy patients

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Hepatobiliary & Pancreatic Diseases International 2018年第6期17卷 546-552页

作者： Min-Gui Han Eunae Cho chang-hwan Park Chung-hwan Jun Seon-Young Park Division of Gastroenterology Department of Internal MedicineChonnam National University Hospital42Jaebong-roDong-KuGwangju 61482Korea

Background: Efficient ampullary intervention is essential for endoscopic retrograde cholangiopancreatography(ERCP) in patients with a prior Billroth II gastrectomy. We retrospectively evaluated the safety and effectiveness of ampullary intervention using fully covered self-expandable metal stents(FCSEMSs) for the management of common bile duct(CBD) stones in a subset of patients with a history of Billroth II gastrectomy. Methods: This retrospective analysis involved patients with a prior Billroth II gastrectomy who underwent ampullary intervention with FCSEMSs for the management of CBD stones. The factors associated with FCSEMSs placement, treatment success, and procedural complications were analyzed. Results: A group of 15 patients(10 males; median age, 78 years) underwent biliary metal stent placement for high degree of CBD angulation(6), small or flat papilla with unclear margin(5), current use of double antiplatelet agents or an anticoagulant(2), unwanted instrumentation of the cystic duct(1), and insecure position of the scope(1). Ampullary intervention with FCSEMSs was successful in all patients. After dilating the ampulla of Vater and building a durable conduit with FCSEMSs immediately, CBD stones were removed successfully from all patients in a single session. A mild post-ERCP pancreatitis occurred in one patient, who recovered without complications. Conclusion: Ampullary intervention with FCSEMSs is safe and effective for the management of CBD stones in a subset of patients with a history of Billroth II gastrectomy.

关键词： Common bile duct stone Endoscopic retrograde cholangiopancreatography Stent placement Stone extraction

Oxidation behavior of high-strength FeCrAl alloys in a high-temperature supercritical carbon dioxide environment

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Progress in Natural Science:Materials International 2018年第6期28卷 731-739页

作者： Hongsheng Chen sung hwan Kim Chongsheng Long Chaewon Kim changheui Jang Department of Nuclear and Quantum Engineering Korea Advanced Institute of Science and Technology Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of China

The oxidation behavior of three high-strength FeCrAl alloys was investigated in supercritical carbon dioxide environment at 650 ℃. After exposure for 500 h, the weight gains of the FeCrAl alloys gradually decreased with increasing Al content. The oxide scales are primarily composed of α-Al;O;and spinel oxides. With increasing Al content, the amount of α-Al;O;increases and the C content decreased in the oxide scale and sub-scale ***, larger（Nb,Mo）C carbides formed in the sub-scale matrix and their number decreased with the increase of Al content.

关键词： High-strength FeCrAl alloy Supercritical carbon dioxide Oxidation α-Al2O3

Improved Hybrid Precoding Technique with Low-Resolution for MIMO-OFDM System

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Computers, Materials & Continua 2021年第8期68卷 2205-2220页

作者： Seulgi Lee Ji-sung Jung Young-hwan You Hyoung-Kyu Song Department of Information and Communication Engineering and Convergence for Intelligent DroneSejong UniversitySeoul05006Korea Department of Computer Engineering Sejong UniversitySeoul05006Korea

This paper proposes an improved hybrid beamforming system based on multiple-input multiple-output orthogonal frequency division multiplexing(MIMO-OFDM)*** proposed beamforming system improves energy efficiency compared to the conventional hybrid beamforming *** sub-connected and full-connected structure are considered to apply the proposed *** the conventional hybrid beamforming,the usage of radio frequency(RF)chains and phase shifter(PS)gives high power and hardware *** this paper,the phase over sampling(POS)with switches(SW)is used in hybrid beamforming system to improve the energy *** POS-SW structure samples the value of analog beamformer to make lower resolution than conventional *** number of output data in POS is decided by the resolution of POS *** limited number of POS decides the resolution of antenna array and the values of POSs are designed from maximum and minimum phase angle antenna *** efficiency without the phase shifter is high although channel capacity is nearly similar with conventional ***,the amplifier with POS-SW system is proposed to improve the BER *** to the data bits,the output signals of POS are *** system with 2,3 and 4 bits is simulated to prove the proposed *** order to overcome the loss of low-resolution system,the amplifier with POS-SW system using channel information is *** average sum-rate of 4 bits system shows the similar performance with the conventional hybrid beamforming *** structure can play an important role by increasing the energy efficiency of the wireless communication system that many antennas are *** is shown that the BER,average sum rate and energy efficiency of the proposed scheme are more improved than the conventional hybrid beamforming system.

关键词： Hybrid beamforming MIMO-OFDM system analog precoding POS-SW