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Recent advances and future challenges for mobile network virtualization

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Science china(Information Sciences) 2017年第4期60卷 5-16页

作者： Xiaofeng TAO Yan HAN Xiaodong xu Ping ZHANG Victor c.M.LEUNG National Engineering Lab for Mobile Network Technologies Beijing University of Posts and Telecommunications State Key Lab of Networking & Switching Technology Beijing University of Posts and Telecommunications Department of Electrical and computer Engineering The University of British Columbia

Recently, network function virtualization(NFV) was proposed as a paradigm shift in the telecommunication industry. Both industry and academia have drawn significant attention in mobile network *** decouples the software implementation of network functions from the underlying hardware, leading to considerable reductions in operating expenses(OPEX) and capital expenses(cAPEX), and facilitating the network deployment. However, as an emerging technology, NFV brings both challenges and opportunities in developing new architectures, applying and deployment. In this paper, we first survey the related work of NFV, and then propose promising research directions in this area.

关键词： network function virtualization mobile networks software defined networking network functions 5G network slicing

APPLIcATION OF NUMERIcAL SIMULATION TO STUDY ON THERMAL cONDUcTION

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Acta Metallurgica Sinica(English Letters) 2004年第1期17卷 16-20页

作者： c.Zhu Z.xu D.E.Wu Tianjin University Tianjin 300074China School of SciencesCivil Aviation University of ChinaTianjin 300300ChinaSchool of SciencesCivil Aviation University of China.Tianjin 300300ChinaSchool of SciencesCivil Aviation University of China.Tianjin 300300China

In this paper, using computer simulation and mathematic experiment method to solve the simplified one dimensional thermal conduction equation and to obtain the temperature distribution in a metal bar when its one end was heated. According to principle of hot expansion, a holograph of temperature distribution in the bar by laser holo-technique was taken. The results of numerical simulation and experiments are in good agreement and a new method for study on thermal conduction by laser holo-technique was found.

关键词： metal bar thermal conduction equation computer simulation holograph

Refractory Ventricular Fibrillation with Underlying coronary Artery Disease after cOVID-19 Vaccine-Kounis Syndrome or coincidence

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case Reports in clinical Medicine 2024年第8期13卷 309-314页

作者： elaine M. c. chau cardiology centre Hong Kong Sanatorium & Hospital Hong Kong SAR China

A 63-year-old man with diabetes and asymptomatic coronary artery disease developed refractory ventricular arrhythmia at 20 hours at rest after his second cOVID-19 vaccine. Despite significant stenosis in the coronary arteries, there was no evidence of acute or old myocardial infarction, heart failure, myocarditis or structural abnormalities on post-mortem to account for the substrate for the fatal arrhythmia. The refractory and incessant nature of the ventricular fibrillation and post-mortem finding of a grossly elevated unexplained IgE level (in the absence of acute myocardial infarction) suggested the possibility of Kounis Syndrome or allergic acute coronary syndrome.

关键词： Refractory Ventricular Fibrillation cOVID-19 Vaccine Kounis Syndrome

Improving the strength and Scc resistance of an Al-5Mg-3Zn alloy with low-angle grain boundary structure

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Journal of Materials Science & Technology 2023年第30期161卷 63-73页

作者： Z.c.Tang W.xu D.Y.Zhao B.Zhang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

The strength of traditional Al-Mg alloys is relatively low because it mainly relies on solid solution *** a third component to form precipitation can improve their strength,but it usually leads to high-stress corrosion cracking(Scc)sensitivity due to the formation of high-density precipitates at grain boundaries(GBs).So far,it is still challenging to improve the strength of Al-Mg alloys without re-ducing Scc ***,a nanostructured Al-5Mg-3 Zn alloy with a good yield strength of 336 MPa and good elongation was successfully *** dynamic plastic deformation and appropriate anneal-ing treatment,near-equiaxed nanograins were introduced in the nanostructured Al-5Mg-3 Zn alloy with a high proportion(71%)of the low-angle grain *** statistical investigations show that the pre-cipitation of active T’phase at GBs has been greatly suppressed in the nanostructured Al-5Mg-3 Zn alloy at sensitized conditions,and the area fraction of GB precipitates is reduced from 72%to 21%,which sig-nificantly decreases the Scc *** study provides guidance for developing advanced Al-Mg alloy with high Scc resistance.

关键词： Al-5Mg-3 Zn alloy Stress corrosion cracking Low angle grain boundary Nanostructured Dynamic plastic deformation

Quaternion Quasi-chebyshev Non-local Means for color Image Denoising

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chinese Journal of Electronics 2023年第3期32卷 397-414页

作者： xu xudong ZHANG Zhihua M.James c.crabbe School of Mathematics Shandong University Wolfson college University of Oxford

Quaternion non-local means(QNLM) denoising algorithm makes full use of high degree self-similarities inside images to suppress the noise, so the similarity metric plays a key role in its denoising *** this study, two improvements have been made for the QNLM: 1) For low level noise, the use of quaternion quasi-chebyshev distance is proposed to measure the similarity of image patches and it has been used to replace the Euclidean distance in the QNLM algorithm. Since the quasi-chebyshev distance measures the maximal distance in all color channels, the similarity of color images measured by quasi-chebyshev distance can capture the structural similarity uniformly for each color channel; 2) For high level noise, quaternion bilateral filtering has been proposed as the preprocessing step in the QNLM algorithm. Denoising simulations were performed on 110 images of landscape, people, and architecture at different noise levels. compared with QNLM, quaternion non-local total variation(QNLTV), and non-local means(NLM)variants(NLTV, NLM after wavelet threshold preprocessing, and the color adaptation of NLM), our novel algorithm not only improved PSNR/SSIM(peak signal to noise rate/structural similarity) and figure of merit values by an average of 2.77 dB/8.96% and 0.0491 respectively, but also reduced processing time.

关键词： Image color analysis Filtering Quaternions Noise reduction color Euclidean distance Filtering algorithms

c^0-Sufficiency,Kuiper-Kuo and Thorn conditions for Non-isolated Singularity

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Acta Mathematica Sinica,English Series 2007年第7期23卷 1251-1256页

作者： xu xu School of Mathematics and Statistics Wuhan University

In this paper, a criterion on the c^0-sufficiency for a function germ with non-isolated singularity is obtained analogously to that of Kuiper-Kuo for the case of isolated singularities. Moreover, the Kuiper Kuo condit... 详细信息

关键词： non-isolated singularity c^0-sufficiency Kuiper-Kuo condition Thom condition

静电纺丝聚偏氟乙烯压电仿生骨膜的生物相容性评价

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中国组织工程研究 2025年第4期29卷 730-737页

作者：赵帅李冬瑶魏岁艳曹怡静许燕徐国强青岛市即墨区人民医院口腔科山东省青岛市266200 新疆乌鲁木齐市口腔医院新疆维吾尔自治区乌鲁木齐市830000 新疆医科大学第一附属医院(附属口腔医院)口腔放射科新疆维吾尔自治区乌鲁木齐市830054 南昌大学附属口腔医院(黏膜牙周科) 江西省南昌市330000 新疆大学机械工程学院新疆维吾尔自治区乌鲁木齐市830047 新疆医科大学第一附属医院(附属口腔医院)口腔修复种植科新疆维吾尔自治区乌鲁木齐市830054 新疆维吾尔自治区口腔医学研究所新疆维吾尔自治区乌鲁木齐市830054

背景:课题组前期研究发现,静电纺丝聚偏氟乙烯仿生骨膜具有良好的细胞相容性,但其生物相容性尚不清楚。目的:评价掺Zn2+、Mg2+聚偏氟乙烯仿生骨膜的生物相容性。方法:取前期研究采用静电纺丝技术制备的聚偏氟乙烯、掺1%Zn2+聚偏氟乙烯、... 详细信息

背景:课题组前期研究发现,静电纺丝聚偏氟乙烯仿生骨膜具有良好的细胞相容性,但其生物相容性尚不清楚。目的:评价掺Zn2+、Mg2+聚偏氟乙烯仿生骨膜的生物相容性。方法:取前期研究采用静电纺丝技术制备的聚偏氟乙烯、掺1%Zn2+聚偏氟乙烯、掺1%Mg2+聚偏氟乙烯、掺1%Zn2++1%Mg2+聚偏氟乙烯仿生骨膜,制备各组仿生骨膜浸提液,选择SD大鼠为实验对象,进行溶血实验、短期全身毒性实验、热源实验,选择豚鼠为实验对象,进行皮肤致敏实验,检测4组仿生骨膜的生物相容性。结果与结论:①溶血实验结果显示,掺1%Zn2+聚偏氟乙烯、掺1%Mg2+聚偏氟乙烯、掺1%Zn2++1%Mg2+聚偏氟乙烯仿生骨膜及聚偏氟乙烯浸提液的溶血率分别为(0.130±0.013)%,(0.149±0.020)%,(0.466±0.018)%,(0.037±0.018)%,符合生物材料血液相容性性标准;②短期全身毒性实验结果显示,4组仿生骨膜浸提液灌胃干预后未引起SD大鼠体质量减轻、摄食量变化及呼吸困难等毒性体征,对大鼠的主要脏器无毒性作用;③热源实验结果显示,掺1%Zn2+聚偏氟乙烯、掺1%Mg2+聚偏氟乙烯、掺1%Zn2++1%Mg2+聚偏氟乙烯及聚偏氟乙烯仿生骨膜浸提液干预后,SD大鼠体温升高值分别为(0.133±0.058),(0.100±0.010),(0.300±0.010),(0.300±0.017)℃,均小于0.6℃,体温升高度数总和均小于1.4℃;④皮肤致敏实验结果显示,4组仿生骨膜浸提液干预后豚鼠皮下未见红斑与水肿。结果表明:聚偏氟乙烯与掺Zn2+、Mg2+聚偏氟乙烯仿生骨膜具有良好的生物相容性。

关键词：静电纺丝聚偏氟乙烯仿生骨膜锌离子镁离子生物相容性

糖尿病性白内障患者术后黄斑水肿的影响因素分析

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国际眼科杂志 2025年第1期25卷 140-143页

作者：李明徐方许之娟胶州中心医院眼科山东省青岛市266300

目的:探讨糖尿病性白内障患者手术治疗后发生黄斑水肿的危险因素,为术后防治提供参考依据。方法:选取青岛市胶州中心医院眼科2022-01/2024-01实施超声乳化手术治疗后且发生黄斑水肿的糖尿病性白内障患者55例55眼作为水肿组,另外年龄与... 详细信息

目的:探讨糖尿病性白内障患者手术治疗后发生黄斑水肿的危险因素,为术后防治提供参考依据。方法:选取青岛市胶州中心医院眼科2022-01/2024-01实施超声乳化手术治疗后且发生黄斑水肿的糖尿病性白内障患者55例55眼作为水肿组,另外年龄与性别基本匹配的接受相同手术治疗但未发生黄斑水肿的糖尿病性白内障患者59例59眼作为对照组,分析房水中干扰素诱导蛋白-10(IP-10)、巨噬细胞趋化蛋白-1(McP-1)、血管内皮生长因子(VEGF)与患者术后黄斑水肿的关系。结果:水肿组的年龄、糖尿病病程、最佳矫正视力(BcVA)、糖化血红蛋白(HbA1c)、肌酐测定值、房水中IP-10、McP-1、VEGF水平均大于对照组(均PcVA、HbA1c升高、肌酐升高及房水中IP-10升高、McP-1升高、VEGF升高是糖尿病性白内障患者手术后发生黄斑水肿的危险因素(均PcVA、HbA1c升高、肌酐升高及房水中IP-10升高、McP-1升高、VEGF升高有关,临床应该针对性地提前给予干预措施。

关键词：糖尿病性白内障超声乳化手术白内障黄斑水肿危险因素

A cAScADIc MULTIGRID ALGORITHM FOR cOMPUTING THE FIEDLER VEcTOR OF GRAPH LAPLAcIANS

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Journal of computational Mathematics 2015年第2期33卷 209-226页

作者： John c. Urschel Jinchao xu Xiaozhe Hu Ludmil T. Zikatanov Department of Mathematics Penn State University Pennsylvania USA Department of Mathematics Tufts University Medford MA 02155 Department of Mathematics Penn State University Pennsylvania USA Institute of Mathematics and Informatics Bulgarian Academy of Sciences Sofia Bulgaria

In this paper, we develop a cascadic multigrid algorithm for fast computation of the Fiedler vector of a graph Laplacian, namely, the eigenvector corresponding to the second smallest eigenvalne. This vector has been found to have applications in fields such as graph partitioning and graph drawing. The algorithm is a purely algebraic approach based on a heavy edge coarsening scheme and pointwise smoothing for refinement. To gain theoretical insight, we also consider the related cascadic multigrid method in the geometric setting for elliptic eigenvalue problems and show its uniform convergence under certain assumptions. Numerical tests are presented for computing the Fiedler vector of several practical graphs, and numerical results show the efficiency and optimality of our proposed cascadic multigrid algorithm.

关键词： Graph Laplacian cascadic Multigrid Fiedler vector Elliptic eigenvalue prob-lems.