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Direct dynamic-simulation approach to trajectory optimization

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Chinese Journal of Aeronautics 2021年第10期34卷 6-19页

作者： Sung Wook HUR Seong Han LEE yong Hyeon NAM Chang-joo KIM Department of Aerospace Information Engineering Konkuk UniversitySeoul 05029Republic of Korea

This paper proposes a new direct method for an efficient trajectory optimization using the point that the dynamics of a deterministic system are uniquely determined by initial states and controls imposed over the time horizon of *** effectively implement this concept,the Hermite spline is adopted to interpolate the continuous controls and the system dynamics are integrated with corresponding control parameters in *** a result,the optimal control problem can be transcribed into a nonlinear programming problem which has no dynamic equality constraints and no intermediate states in its design *** addition,the paper proposes an efficient recursive Jacobian estimation technique and introduces a Jacobian transformation matrix to straightforwardly handle the general state *** properties of the present method are thoroughly investigated through its applications to the trajectory optimization for a soft lunar landing from a parking orbit,including the detailed analyses for the de-orbiting *** computed results are compared with those using the pseudo-spectral method to demonstrate an extreme outperformance of the proposed method in the aerospace applications over the traditional direct method.

关键词： Trajectory optimization Direct method Hermite spline interpolation Pseudo-spectral integrator Soft lunar landing

Polysplenia syndrome with preduodenal portal vein detected in adults

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World Journal of Gastroenterology 2008年第41期14卷 6418-6420页

作者： Hyung-Il Seo Tae yong Jeon Mun Sup sim Suk Kim Department of Surgery Postgraduate School of Medicine and Medical Research Institute Pusan National University Department of Radiology Postgraduate School of Medicine Pusan National University

Polysplenia syndrome, defined as the presence of multiple spleens of almost equal volume, is a rare condition involving congenital anomalies in multiple organ systems. We report this anomaly in a 41-year-old female who underwent a left lateral sectionectomy due to recurrent cholangitis and impacted left lateral duct stones. Polysplenia syndrome with preduodenal vein was diagnosed preoperatively by computed to-mography (CT) and surgery was done safely. Although the polysplenia syndrome with preduodenal portal vein (PDPV) in adult is rarely encountered, surgeons need to understand the course of the portal vein and exercise caution in approaching the biliary tract.

关键词： Polysplenia Polysplenia syndrome Preduodenal portal vein Intrahepatic duct stones Congenital anomaly

Ethanolic extract of dandelion(Taraxacum mongolicum) induces estrogenic activity in MCF-7 cells and immature rats

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Chinese Journal of Natural Medicines 2015年第11期13卷 808-814页

作者： Seung Min Oh Ha Ryong Kim yong joo Park yong Hwa Lee Kyu Hyuck Chung Fusion Technology Laboratory Hoseo University School of Pharmacy Sungkyunkwan University

Plants of the genus Taraxacum, commonly known as dandelions, are used to treat breast cancer in traditional folk medicine. However, their use has mainly been based on empirical findings without sufficient scientific evidence. Therefore, we hypothesized that dandelions would behave as a Selective estrogen receptor modulator （SERM） and be effective as hormone replacement therapy （HRT） in the postmenopausal women. In the present study, in vitro assay systems, including cell proliferation assay, reporter gene assay, and RT-PCR to evaluate the mRNA expression of estrogen-related genes （pS2 and progesterone receptor, PR）, were performed in human breast cancer cells. Dandelion ethanol extract （DEE） significantly increased cell proliferation and estrogen response element （ERE）-driven luciferase activity. DEE significantly induced the expression of estrogen related genes such as pS2 and PR, which was inhibited by tamoxifen at 1 gmol L-1. These results indicated that DEE could induce estrogenic activities mediated by a classical estrogen receptor pathway. In addition, immature rat uterotrophic assay was carried out to identify estrogenic activity of DEE in vivo. The lowest concentration of DEE slightly increased the uterine wet weight, but there was no significant effect with the highest concentration of DEE. The results demonstrate the potential estrogenic activities of DEE, providing scientific evidence supporting their use in traditional medicine.

关键词： Dandelion extract Estrogenic activity MCF-7 cells Immature rat uterotrophic assay

Performance evaluation of the use of tire-derived fuel fly ash as mineral filler in hot mix asphalt concrete

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Journal of Traffic and Transportation Engineering(English Edition) 2020年第2期7卷 249-258页

作者： Min Ju Choi yong joo Kim Hyeok Jung Kim Jae Jun Lee BILTZONE Co. Ltd.Hwaseong 18514South Korea Korea Institute o f Civil Engineering and Building Technology Goyang-Si 10223South Korea Industry-Academic Cooperation Foundation Center Hankyong National UniversityAnseong-si 17579South Korea Department of Civil Engineering Chonbuk National UniversityJeonju 54896South Korea

According to deplete natural resources and need to protect the environment,the demand of a usage of waste material has significantly *** studies are currently being carried out on the development of innovative and environmentally friendly materials for securing the safety of road users and improving the performance and durability of *** example,studies are currently being conducted on the use of waste tires as a substitute for currently used *** the development of the automobile industry,the amount of waste tire has continuously increased in accordance with the increased vehicle ***-derived fuel(TDF)has been used as a fuel source with generated TDF fly *** filler,made of fine mineral particles of a physical size passing the number 200 standard mesh sieve(75 micron),plays an important role in asphalt mixtures *** paper presents an application of TDF fly ash as filler in hot mix asphalt(HMA).In this study,the performance of TDF fly ash was confirmed through a comparison with three other mineral fillers:stone dust,cement,and hydrated *** tests including Marshall stability test,moisture sensitivity test,dynamic immersion test,and a wheel tracking test were performed to investigate the difference in the behaviors of the samples with different parameters considered in this *** results show that the mechanical performance of hot mix asphalt using TDF fly ash satisfied the quality standard specification of the Ministry of Land,Infrastructure and Transport(MOLIT),*** can be concluded that the use of TDF fly ash as a mineral filler in HMA not only satisfied the mechanical properties,but also reduced the volume of the pollutants waste in the environment.

关键词： Asphalt mixture TDF fly ash Marshal stability Moisture sensitive TSR

等离子射流在模拟液体发射药中扩展特性的数值模拟

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含能材料 2024年第5期32卷 510-517页

作者：薛皓琦余永刚南京理工大学能源与动力工程学院江苏南京210094

为了深入认识液体工质电热化学炮中等离子射流的点火过程,开展了等离子射流在液体发射药LP1846模拟工质中扩展特性的研究,建立了等离子射流在液体中扩展的二维轴对称非稳态数学模型,并基于液体工质为水的文献实验进行模型验证。在此基... 详细信息

为了深入认识液体工质电热化学炮中等离子射流的点火过程,开展了等离子射流在液体发射药LP1846模拟工质中扩展特性的研究,建立了等离子射流在液体中扩展的二维轴对称非稳态数学模型,并基于液体工质为水的文献实验进行模型验证。在此基础上对等离子射流在LP1846液体发射药模拟工质中的扩展过程进行数值模拟,分析等离子射流在扩展过程中形态的变化以及射流场压力、速度和温度的分布特性。结果表明,扩展过程中由于Taylor-Helmholtz不稳定性,等离子射流和液体发射药模拟工质两相间存在湍流掺混现象,并随着扩展逐渐加剧,表现为射流头部凸出并逐渐轴向拉长形成尖头,同时射流卷吸液体发射药模拟工质在Taylor空腔中产生液滴,且数量逐渐增多。此外,等离子射流扩展过程中近喷孔处由于液体发射药模拟工质回流而出现颈缩现象。射流场由于膨胀波-压缩波交替作用而存在波动现象,且在近喷孔处尤为剧烈,表现为压力场呈现高低压相间分布,速度场也呈类似分布。

关键词：等离子射流液体工质扩展特性湍流掺混数值模拟发射药

Metastasis to the gallbladder:A single-center experience of 20 cases in South Korea

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World Journal of Gastroenterology 2009年第38期15卷 4806-4809页

作者： Won Jae Yoon yong Bum Yoon Youn joo Kim Ji Kon Ryu yong-Tae Kim Department of Internal Medicine Seoul National University College of Medicine Department of Internal Medicine Korea Cancer Center Hospital

AIM： To evaluate the clinicopathologic characteristics of patients with metastases to the gallbladder （MGBs）. METHODS： We performed a single-center retrospective study of 20 patients with MGBs diagnosed pathologically from 1999 to 2007. RESULTS： Among 417 gallbladder （GB） malignancies, 20 （4.8%） were MGBs. The primary malignancies originated from the stomach （n = 8）, colorectum （n = 3）, liver （n = 2）, kidney （n = 2）, skin （n = 2）, extrahepatic bile duct （n = 1）, uterine cervix （n = 1）, and appendix （n = 1）. Twelve patients were diagnosed metachronously, presenting with cholecystitis （n = 4）, abdominal pain （n = 2）, jaundice （n = 1）, weight loss （n = 1）, and serum CA 19-9 elevation （n = 1）; five patients were asymptomatic. The median survival after the diagnosis of MGB was 8.7 mo. On Cox regression analysis, R0 resection was the only factor associated with a prolonged survival [hazard ratio （HR）： 0.01, P = 0.002]; presentation with cholecystitis was associated with poor survival （HR： 463.27, P = 0.006）. CONCLUSION： MGBs accounted for 4.8% of all pathologically diagnosed GB malignancies. The most common origin was the stomach. The median survival of MGI3 was 8.7 mo.

关键词： Gallbladder Neoplasms Gastrointestinalneoplasms Neoplasm metastasis Biliary tract neoplasms

Effect of annealing on two different niobium-clad stainless steel PEMFC bipolar plate materials

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中国有色金属学会会刊：英文版 2009年第B9期19卷 56-60页

作者： Sung-Tae HONG Dae-Wook KIM yong-joo YOU K.Scott WEIL School of Mechanical and Automotive Engineering University of Ulsan Department of Material Science and Engineering University of Ulsan Pacific Northwest National Laboratory

Niobium (Nb)-clad stainless steels(SS) produced via roll bonding are being considered for use in the bipolar plates of polymer electrolyte membrane fuel cell(PEMFC) stacks. Because the roll bonding process induces substantial work hardening in the constituent materials, thermal annealing is used to restore ductility to the clad sheet so that it can be subsequently blanked, stamped and dimpled in forming the final plate component. Two roll bonded materials, niobium clad 340L stainless steel (Nb/340L SS) and niobium clad 434 stainless steel (Nb/434 SS) were annealed under optimized conditions prescribed by the cladding manufacturer. Comparative mechanical testing conducted on each material before and after annealing shows significant improvement in ductility in both cases. However, corresponding microstructural analyses indicate an obvious difference between the two heat treated materials. During annealing, an interlayer with thick less than 1 μm forms between the constituent layers in the Nb/340L SS, whereas no interlayer is found in the annealed Nb/434 SS material. Prior work suggests that internal defects potentially can be generated in such an interlayer during metal forming operations. Thus, Nb/434 SS may be the preferred candidate material for this application.

关键词：质子交换膜燃料不锈钢材料双极板材料退火条件复合板铌聚合物电解质微观结构分析

Relief of YAP-mediated inhibition by IKKε promotes innate antiviral immunity

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Cellular & Molecular Immunology 2018年第6期15卷 642-644页

作者： Nayoung Kim Yun-yong Park Chul Hyun joo Hun Sik Kim Department of Convergence Medicine Asan Medical CenterUniversity of Ulsan College of MedicineSeoul 05505Korea Asan Institute for Life Sciences Asan Medical CenterUniversity of Ulsan College of MedicineSeoul 05505Korea Department of Microbiology Asan Medical CenterUniversity of Ulsan College of MedicineSeoul 05505Korea Department of Biomedical Sciences Asan Medical CenterUniversity of Ulsan College of MedicineSeoul 05505Korea

The innate immune response to invading viruses is critical for the mounting of protective immunity,in which type I interferons(IFN),for example,IFN-αandβ,are potent effector molecules.1 Most cell types,particularly fibroblasts and epithelial cells,produce IFN-β,whereas hematopoietic cells,notably plasmacytoid dendritic cells,are the predominant sources of IFN-α.IFNs potently stimulate a variety of innate and adaptive immune cells,including macrophages,NK cells and T *** binding of type I IFN to its cognate receptor triggers the activation of the Janus kinase signal transducer and activator of transcription pathway,which results in the transcription of IFNstimulated genes that play key roles in host resistance to viral infections.

关键词： immunity protective mount

SEQUENCES OF POWERS OF TOEPLITZ OPERATORS ON THE BERGMAN SPACE

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Acta Mathematica Scientia 2021年第3期41卷 657-669页

作者： yong CHEN Kei Ji IZUCHI Kou Hei IZUCHI Young joo LEE Department of Mathematics Hangzhou Normal UniversityHangzhou 311121China Department of Mathematics Niigata UniversityNiigata 950-2181Japan Department of Mathematics Faculty of EducationYamaguchi UniversityYamaguchi 753-8511Japan Department of Mathematics Chonnam National UniversityGwangju 61186Korea

We consider Toeplitz operators Tu with symbol u on the Bergman space of the unit ball,and then study the convergences and summability for the sequences of powers of Toeplitz *** first charactreize analytic symbolsφfor which the sequence Tφ*kf or Tφkf converges to 0 or∞as k→∞in norm for every nonzero Bergman function ***,we characterize analytic symbolsφfor which the norm of such a sequence is summable or not *** also study the corresponding problems on an infinite direct sum of Bergman spaces as a generalization of our result.

关键词： Bergman space Toeplitz operator