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An accelerated K-means clustering algorithm using selection and erasure rules

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Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第10期13卷 761-768页

作者： Suiang-Shyan LEE ja-Chen LIN Department of Computer Science National Chiao Tung University

The K-means method is a well-known clustering algorithm with an extensive range of applications,such as biological classification,disease analysis,data mining,and image ***,the plain K-means method is not fast when the number of clusters or the number of data points becomes large.A modified K-means algorithm was presented by Fahim et al.(2006).The modified algorithm produced clusters whose mean square error was very similar to that of the plain K-means,but the execution time was *** this study,we try to further increase its *** are two rules in our method:a selection rule,used to acquire a good candidate as the initial center to be checked,and an erasure rule,used to delete one or many unqualified centers each time a specified condition is *** clustering results are identical to those of Fahim et al.(2006).However,our method further cuts computation time when the number of clusters *** mathematical reasoning used in our design is included.

关键词： K-means clustering Acceleration Vector quantization Selection Erasure

ON TRANSMISSION PROBLEM FOR VISCOELASTIC WAVE EQUATION WITH A LOCALIZED A NONLINEAR DISSIPATION

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Acta Mathematica Scientia 2013年第2期33卷 362-374页

作者： Jeong ja BAE Seong Sik KIM Department of Mathematics Dongeui UniversityPusan 614-714Korea

In this article, we consider the global existence and decay rates of solutions for the transmission problem of Kirchhoff type wave equations consisting of two physically different types of materials, one component being a Kirchhoff type wave equation with time dependent localized dissipation which is effective only on a neighborhood of certain part of boundary, while the other being a Kirchhoff type viscoelastic wave equation with nonlinear memory

关键词： Existence of solution uniform decay transmission problem boundary valueproblem localized dissipation

Spectrum and Singular Integrals on a New Weighted Function Space

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Acta Mathematica Sinica,English Series 2018年第11期34卷 1692-1702页

作者： Hee Chul PAK Young ja PARK Department of Mathematics Dankook University Dandae-ro 119 Dongnam-gu Cheonan-si Chungnam 31116 Republic of Korea Department of Mathematics Hoseo University Hoeo-ro 79 Asan-si Chungnam 31499 Republic of Korea

We introduce a new function space that is much finer than the classical Lebesgue spaces, and investigate the continuity and the discontinuity of the Calderon-Zygmund operators on the new weighted spaces. In order to identify the continuity of singular integrals, we prove an interpolation theorem on the new spaces and propose a concept of the spectrum of base functions.

关键词： Function spaces singular integrals interpolation Calderdn Zygmund operators Holder's inequality L log L

Improved block matching approach to fast disparity estimation

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Journal of Systems Engineering and Electronics 2009年第6期20卷 1278-1285页

作者： Tao Tangfei ja Choon Koo Hyouk Ryeol Choi School of Mechanical Engineering Xi'an Jiaotong Univ. Xi'an 710049 P. R. China State Key Lab. for Manufacturing Systems Engineering Xi'an 710049 P. R. China School of Mechanical Engineering Sungkyunkwan Univ. Suwon Republic of Korea

An improved block matching approach to fast disparity estimation in machine vision applications is proposed, where the matching criterion is the sum of the absolute difference（SAD）.By evaluating the lower bounds, which become increasingly tighter for the matching criteria, the method tries to successively terminate unnecessary computations of the matching criteria between the reference block in one image and the ineligible candidate blocks in another *** also eliminates the ineligible blocks as early as possible, while ensuring the optimal disparity of each ***, the proposed method can further speed up the elimination of ineligible candidate blocks by efficiently using the continuous constraint of disparity to predict the initial disparity of each *** performance of the new algorithm is evaluated by carrying out a theoretical analysis, and by comparing its performance with the disparity estimation method based on the standard block *** results demonstrate that the proposed algorithm achieves a computational cost reduction of over 50.5% in comparision with the standard block matching method.

关键词： machine vision block matching disparity estimation sum of the absolute difference.

Mechanical Behaviour of Composite Bioactive Bone Cements Consisting of Two Different Types of Surface Treated Hydroxyapatite as Filler

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Journal of Wuhan University of Technology(Materials Science) 2005年第B12期20卷 10-12页

作者： S Deb ja Roether Department of Biomaterials King's College London School of Dentistry at the Guy's King's & St Thomas Hospital Guy's Tower Guy's Hospital London Bridge London SE 1 9RT UK

Bioactive bone cements based on a paste-paste system for orthopaedic applications were developed consisting of hydroxyapatite （ HA ） filler panicles in a methacrylate matrix comprising urethane dimethacrylate （ UDMA ） and triethylene glycol dimethacrylate （ TEGDMA ）. To improve the interface between inorganic filler and organic matrix the HA panicles were subjected to two different surface treatment methods, using polyacrylic acid （PAA） and γ-methacryloxy propyl trimethoxy silane （γMPS）. The aim of the present study was to determine the influence of surface treatment and the inclusion of multifunctional methacrylates on the mechanical properties, namely 3-point flexural strength （FS） and fracture toughness of the cements and the effect of ageing in simulated body fluid. Comparing the mechanical properties of the two cements, the γMPS- HA cement showed that the fracture toughness of the experimental bone cements were significantly greater （ p 〈 0.001） compared to that of the PMMA cement, whereas PAA-HA containing cement had strength vollues around 20% lower. Interestingly, PAA was found to be more effective in improving the interface as the PAA treated HA cement （ UTHAPPA ） maintained its strength on immersion in SBF, suggesting that PAA provided a coupling, which was less sensitive to moisture, a similar trend was also observed with the inclusion of the carboxyl containing multifunctional methacrylates.

关键词： bioactive bone cements coupling agents composites polyacrylic acid

Current issues in locally advanced colorectal cancer treated by preoperative chemoradiotherapy

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World Journal of Gastroenterology 2014年第8期20卷 2023-2029页

作者： In ja Park Chang Sik Yu Department of Colon and Rectal Surgery Asan Medical CenterUniversity of Ulsan College of MedicineSeoul 138-736South Korea

In patients with locally advanced rectal cancer, preoperative chemoradiotherapy has proven to significantly improve local control and cause lower treatment-related toxicity compared with postoperative adjuvant treatment. Preoperative chemoradiotherapy followed by total mesorectal excision or tumor specific mesorectal excision has evolved as the standard treatment for locally advanced rectal cancer. The paradigm shift from postoperative to preoperative therapy has raised a series of concerns however that have practical clinical implications. These include the method used to predict patients who will show good response, sphincter preservation, the application of conservative management such as local excision or “wait-and-watch” in patients obtaining a good response following preoperative chemoradiotherapy, and the role of adjuvant chemotherapy. This review addresses these current issues in patients with locally advanced rectal cancer treated by preoperative chemoradiotherapy.

关键词： Colorectal cancer Rectal cancer Preoperative chemoradiotherapy Conservative Response

表面活性剂对CaO_(2)修复石油烃污染土壤的影响研究

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环境科技 2024年第2期37卷 1-6,12页

作者：张祥孙勇向甲甲上海市政工程设计研究总院(集团)有限公司上海200092 上海申环环境工程有限公司上海200092

将合成的纳米级过氧化钙(nCaO_(2))用于石油烃污染土壤修复,研究过氧化钙(CaO_(2))、柠檬酸(CA)螯合二价铁(Fe(Ⅱ))投加量对石油烃去除效果的影响,并将不同表面活性剂对石油烃氧化的影响进行比较。结果表明,随着CaO_(2)或CA螯合Fe(Ⅱ)... 详细信息

将合成的纳米级过氧化钙(nCaO_(2))用于石油烃污染土壤修复,研究过氧化钙(CaO_(2))、柠檬酸(CA)螯合二价铁(Fe(Ⅱ))投加量对石油烃去除效果的影响,并将不同表面活性剂对石油烃氧化的影响进行比较。结果表明,随着CaO_(2)或CA螯合Fe(Ⅱ)的投加量增大,石油烃去除率均呈先增后降趋势。当n(CaO_(2)):n(Fe(Ⅱ)):n(CA)为4:1:1时,石油烃去除效果最佳,达到70.98%。十二烷基硫酸钠和曲拉通X-100对土壤中石油烃均有较好的增溶效果。质量浓度为3g/L的十二烷基硫酸钠对石油烃的降解可起促进作用,而曲拉通X-100则不利于石油烃的降解。

关键词：过氧化钙石油烃表面活性剂化学氧化纳米材料

Bound lipids in lacustrine sediments in Guchenghu Lake, East China

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Chinese Science Bulletin 1997年第21期42卷 1817-1820页

作者： Zhang, G Sheng, GY Fu, ja Chinese Acad Sci Guangzhou Inst Geochem Guangzhou 510640 Peoples R China

BIOMARKERS used as indicators of the paleoclimatic and paleoenvironmental changes are re-quired to be bio-specific in origin and be stable in the early diagenesis process. The input ofplenty of land-derived organics, as well as possible changes in the early diagenesis process,made the lipid composition of inland lacustrine sediments more complicated, and, as a result,the bio-indicating significance of some biomarkers often become obscured. Except for

关键词： bound lipids composition sources paleoenvironmental changes.

山楂叶总黄酮通过miR-21a-5p对血管紧张素Ⅱ诱导的心肌细胞肥大的影响

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中国临床药理学杂志 2024年第15期40卷 2182-2186页

作者：田林燕朱冉代聚平王佳佳张斌南阳医学高等专科学校内科教研室河南南阳473000 南阳医学高等专科学校临床实训室河南南阳473000 南阳医学高等专科学校第一附属医院心血管内科河南南阳473000 南阳医学高等专科学校第一附属医院病理科河南南阳473000

目的探讨山楂叶总黄酮对血管紧张素Ⅱ(AngⅡ)诱导的心肌肥大的影响,及其可能作用机制。方法将H9c2细胞分为对照组(正常培养),模型组(100 nmol·L^(-1)AngⅡ处理24 h),低、中、高剂量实验组(先给予100 nmol·L^(-1)AngⅡ处理24 h后,再分... 详细信息

目的探讨山楂叶总黄酮对血管紧张素Ⅱ(AngⅡ)诱导的心肌肥大的影响,及其可能作用机制。方法将H9c2细胞分为对照组(正常培养),模型组(100 nmol·L^(-1)AngⅡ处理24 h),低、中、高剂量实验组(先给予100 nmol·L^(-1)AngⅡ处理24 h后,再分别给予25、50、100 mg·L^(-1)的山楂叶总黄酮处理24 h),anti-miR-NC、anti-miR-21a-5p组(分别转染anti-miR-NC、anti-miR-21a-5p后,给予100 nmol·L^(-1)AngⅡ处理24 h),miR-NC+高剂量组和miR-21a-5p+高剂量组(分别转染miR-NC、miR-21a-5p mimics,再给予100 nmol·L^(-1)AngⅡ+100 mg·L^(-1)山楂叶总黄酮各处理24 h)。用CCK-8法和流式细胞术检测细胞活力和凋亡情况,用实时荧光定量聚合酶链反应法检测miR-21a-5p的表达水平,用蛋白质印迹法检测环氧化酶-2(COX2)/前列腺素E2(PGE2)的表达水平。结果对照组、模型组和高剂量实验组的细胞活力分别为1.03±0.09、0.51±0.05和0.93±0.08,凋亡率分别为(7.69±0.61)%、(23.04±1.82)%和(9.43±0.71)%,miR-21a-5p表达水平分别为1.00±0.09、2.43±0.18和1.09±0.08,COX2蛋白相对表达水平分别为0.42±0.03、0.85±0.08和0.40±0.04,PGE2蛋白相对表达水平分别为0.34±0.03、0.75±0.07和0.35±0.03,模型组的上述指标与高剂量实验组和对照组相比,在统计学上差异均有统计学意义(均P0.05)。anti-miR-NC组、anti-miR-21a-5p组、miR-NC+高剂量组和miR-21a-5p+高剂量组的细胞活力分别为0.52±0.04、1.12±0.08、0.94±0.09和0.57±0.04,凋亡率分别为(23.04±1.82)%、(9.86±0.73)%、(9.47±0.64)%和(24.96±1.94)%,miR-21a-5p表达水平分别为1.00±0.10、0.43±0.04、1.00±0.09和2.12±0.18,COX2蛋白相对表达水平分别为0.86±0.05、0.39±0.04、0.41±0.03、0.78±0.07,PGE2蛋白相对表达水平分别为0.74±0.06、0.38±0.07、0.36±0.02、0.71±0.05,anti-miR-21a-5p组的上述指标与anti-miR-NC组比较,miR-21a-5p+高剂量组的上述指标与miR-NC+高剂量组比较,在统计学上差异均有统计学意义(均P0.05)。结论山楂叶总黄酮通过调控miR-21a-5p和COX2/PGE2通路的表达,从而抑制AngⅡ诱导的心肌肥大。

关键词：山楂叶总黄酮心肌肥大血管紧张素Ⅱ 细胞增殖凋亡