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Mass-front velocity of dry granular flows influenced by the angle of the slope to the runout plane and particle size gradation

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Journal of Mountain Science 2016年第2期13卷 234-245页

作者： FAN Xiao-yi TIAN Shu-jun ZHANG You-yi State Key Laboratory of Geo-Hazard Prevention and Geo-Environment Protection Chengdu University of Technology School of Civil Engineering and Architecture Southwest University of Science and Technology

The mass-front velocities of granular flows results from the joint action of particle size gradations and the underlying ***,because of the complexity of friction during flow movement,details such as the slope-toe impedance effects and momentum-transfer mechanisms have not been completely explained by theoretical analyses,numerical simulations,or field *** study the mass-front velocity of dry granular flows influenced by the angle of the slope to the runout plane and particle size gradations we conducted model experiments that recorded the motion of rapid and long-runout rockslides or *** tests were conducted using slope angles of 25°,35°,45°,and 55° and three particle size *** resulting mass-front motions consisted of three stages:acceleration,velocity maintenance,and *** existing methods of velocity prediction could not explain the slowing effect of the slope toe or the momentum-transfer steady velocity *** the slope angle increased from 25° to 55°,the mass-front velocities dropped significantly to between 44.4% and59.6% of the peak velocities and energy lossesincreased from 69.1% to 83.7% of the initial,*** velocity maintenance stages occurred after the slope-toe and mass-front velocity *** this stage,travel distances increased as the angles increased,but the average velocity was greatest at 45°.At a slope angle of 45°,as the median particle size increased,energy loss around the slope toe decreased,the efficiency of momentum transfer increased,and the distance of the velocity maintenance stage *** presented an improved average velocity formula for granular flow and a geometrical model of the energy along the flow line.

关键词： Granular flow Angle of slope Runout plane Particle size gradation Mass-front velocity Energy-profile

Relativistic transformation between τ and TCB for Mars missions: Fourier analysis on its accessibility with clock offset

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Research in Astronomy and Astrophysics 2013年第11期13卷 1358-1362页

作者： jun-Yang Pan yi Xie Department of Astronomy Nanjing University Key Laboratory of Modern Astronomy and Astrophysics Nanjing University Ministry of Education

In the context of the fact that Einstein＇s general relativity has become an inevitable part of deep space missions, we will extend previous works on relativistic transformation between the proper time ^- of a clock onboard a spacecraft orbiting Mars and the Barycentric Coordinate Time （TCB） by taking the clock offset into ac- count and investigate its accessibility by Fourier analysis on the residuals after fitting the ^--TCB curve in terms of n-th order polynomials. We find that if the accuracy of a clock can achieve better than ~ 10-5 s or ~ 10-6 s （depending on the type of clock offset） in one year after calibration, the relativistic effects on the difference between 7- and TCB will need to be carefully considered.

关键词： reference systems -- time -- methods: numerical-- space vehicles

Reduce the decoding complexity: segment linear network coding

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The Journal of China Universities of Posts and Telecommunications 2013年第6期20卷 55-61页

作者： GUO yi-jun HAO Jian-jun YUE Guang-xin School of Telecommunication Engineering Beijing University of Posts and Telecommunications

The throughput gain obtained by linear network coding （LNC） grows as the generation size increases, while the decoding complexity also grows exponentially. High decoding complexity makes the decoder to be the bottleneck for high speed and large data transmissions. In order to reduce the decoding complexity of network coding, a segment linear network coding （SLNC） scheme is proposed. SLNC provides a general coding structure for the generation-based network coding. By dividing a generation into several segments and restraining the coding coefficients of the symbols within the same segment, SLNC splits a high-rank matrix inversion into several low-rank matrix inversions, therefore reduces the decoding complexity dramatically. In addition, two coefficient selection strategies are proposed for both centrally controlled networks and distributed networks respectively. The theoretical analysis and simulation results prove that SLNC achieves a fairly low decoding complexity at a cost of rarely few extra transmissions.

关键词： SLNC generation-based network coding random LNC decoding complexity extra transmission cost

Learning label-specific features for decomposition-based multi-class classification

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Frontiers of Computer Science 2023年第6期17卷 101-110页

作者： Bin-Bin JIA jun-ying LIU jun-yi HANG Min-Ling ZHANG College of Electrical and Information Engineering Lanzhou University of TechnologyLanzhou 730050China School of Computer Science and Engineering Southeast UniversityNanjing 210096China Key Laboratory of Computer Network and Information Integration(Ministry of Education) Southeast UniversityNanjing 210096China

Multi-class classification can be solved by decomposing it into a set of binary classification problems according to some encoding rules,e.g.,one-vs-one,one-vs-rest,error-correcting output *** works solve these binary classification problems in the original feature space,while it might be suboptimal as different binary classification problems correspond to different positive and negative *** this paper,we propose to learn label-specific features for each decomposed binary classification problem to consider the specific characteristics containing in its positive and negative ***,to generate the label-specific features,clustering analysis is respectively conducted on the positive and negative examples in each decomposed binary data set to discover their inherent information and then label-specific features for one example are obtained by measuring the similarity between it and all cluster *** clearly validate the effectiveness of learning label-specific features for decomposition-based multi-class classification.

关键词： machine learning multi-class classification error-correcting output codes label-specific features

Vectorial approximations of infinite-dimensional covariance descriptors for image classification

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Computational Visual Media 2017年第4期3卷 379-385页

作者： Jie-yi Ren Xiao-jun Wu School of Io T Engineering Jiangnan UniversityWuxi 214122China

The class of symmetric positive definite(SPD)matrices,especially in the form of covariance descriptors(Cov Ds),have been receiving increased interest for many computer vision *** descriptors offer a compact way of robustly fusing different types of features with measurement *** examples of applying Cov Ds addressing various classification problems

关键词： covariance infinite Riemannian symmetric matrices applying dimensionality classifier Euclidean kernel

基于自适应续流比的混合式步进电机转矩脉动抑制方法

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陕西科技大学学报 2025年第1期43卷 142-151,202页

作者：王焜刘宝泉刘艺张浩铭刘俊陕西科技大学电气与控制工程学院陕西西安710021 西安西电高压开关有限责任公司陕西西安710018

混合式步进电机细分驱动存在较大的电流纹波,导致转矩脉动明显.通过分析H桥驱动电路的续流过程,提出一种基于自适应续流比的混合式步进电机转矩脉动抑制方法.该方法利用环型分配器产生的细分指令电流i ref与实际电流i相比较,以区分当前... 详细信息

混合式步进电机细分驱动存在较大的电流纹波,导致转矩脉动明显.通过分析H桥驱动电路的续流过程,提出一种基于自适应续流比的混合式步进电机转矩脉动抑制方法.该方法利用环型分配器产生的细分指令电流i ref与实际电流i相比较,以区分当前时刻所需的续流模式.在快速续流模式下,实时监测电流指令与实际电流的差值Δi ref,通过自适应系数k动态调节续流时间,直至电机相电流快速下降至给定电流i ref后切换至缓慢续流模式.对续流时长与快速续流占总续流时间的比例自适应调节以适应不同工况下步进电机的平稳运行,有效降低了转矩脉动.最后,搭建MATLAB/Simulink仿真平台并进行实验验证,结果表明,与传统混合续流控制相比,所提方法能够有效减小步进电机的转矩脉动.

关键词：混合式步进电机自适应续流比电流纹波转矩脉动

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Reliability of flip-chip bonded RFID die using anisotropic conductive paste hybrid material

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Transactions of Nonferrous Metals Society of China 2011年第A01期21卷 175-181页

作者： jun-Sik LEE jun-Ki kim Mok-Soon kim Namhyun KANG Jong-Hyun LEE Advanced Joining Technology Team/Microjoining Center Korea Institute of Industrial Technology(KITECH) Yeonsu-gu Incheon 406-840 Korea School of Materials Science & Engineering Inha University Department of Materials Science & Engineering Pusan National University Department of Materials Science & Engineering Seoul National University of Technology

A reliability of flip-chip bonded die as a function of anisotropic conductive paste (ACP) hybrid materials, bonding conditions, and antenna pattern materials was investigated during the assembly of radio frequency identification(RFID) inlay. The optimization condition for flip-chip bonding was determined from the behavior of bonding strength. Under the optimized condition, the shear strength for the antenna printed with paste-type Ag ink was larger than that for Cu antenna. Furthermore, an identification distance was varied from the antenna materials. Comparing with the Ag antenna pattern, the as-bonded die on Cu antenna showed a larger distance of identification. However, the long-term reliability of inlay using the Cu antenna was decreased significantly as a function of aging time at room temperature because of the bended shape of Cu antenna formed during the flip-chip bonding process.

关键词： RFID inlay ACP flip-chip, bonding process reliability

SARS-CoV-2 aberrantly elevates mitochondrial bioenergetics to induce robust virus propagation

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Signal Transduction and Targeted Therapy 2024年第6期9卷 2702-2715页

作者： Hye Jin Shin Wooseong Lee Keun Bon Ku Gun Young Yoon Hyun-Woo Moon Chonsaeng kim Mi-Hwa kim Yoon-Sun yi Sangmi jun Bum-Tae kim Jong-Won Oh Aleem Siddiqui Seong-jun kim Department of Convergent Research of Emerging Virus Infection Korea Research Institute of Chemical TechnologyDaejeon 34114Republic of Korea Gyeongnam Biohealth Research Center Gyeongnam Branch InstituteKorea Institute of ToxicologyJinju 52834Republic of Korea Center for Research Equipment Korea Basic Science InstituteCheongjuChungcheongbuk-do 28119Republic of Korea Department of Biotechnology Yonsei UniversitySeoul 03722Republic of Korea Division of Infectious Diseases School of MedicineUniversity of CaliforniaSan DiegoLa JollaCA 92093USA Present address:Department of Microbiology Chungnam National University School of MedicineDaejeon 35015Republic of Korea

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is a‘highly transmissible respiratory pathogen,leading to severe multiorgan ***,knowledge regarding SARS-CoV-2-induced cellular alterations is *** this study,we report that SARSCoV-2 aberrantly elevates mitochondrial bioenergetics and activates the EGFR-mediated cell survival signal cascade during the early stage of viral ***-CoV-2 causes an increase in mitochondrial transmembrane potential via the SARS-CoV-2 RNAnucleocapsid cluster,thereby abnormally promoting mitochondrial elongation and the OXPHOS process,followed by enhancing ATP ***,SARS-CoV-2 activates the EGFR signal cascade and subsequently induces mitochondrial EGFR trafficking,contributing to abnormal OXPHOS process and viral *** EGFR inhibitors remarkably reduce SARS-CoV-2 propagation,among which vandetanib exhibits the highest antiviral *** of SARS-CoV-2-infected cells with vandetanib decreases SARS-CoV-2-induced EGFR trafficking to the mitochondria and restores SARS-CoV-2-induced aberrant elevation in OXPHOS process and ATP generation,thereby resulting in the reduction of SARS-CoV-2 ***,oral administration of vandetanib to SARS-CoV-2-infected hACE2 transgenic mice reduces SARS-CoV-2 propagation in lung tissue and mitigates SARS-CoV-2-induced lung *** also exhibits potent antiviral activity against various SARS-CoV-2 variants of concern,including alpha,beta,delta and omicron,in in vitro cell culture *** together,our findings provide novel insight into SARS-CoV-2-induced alterations in mitochondrial dynamics and EGFR trafficking during the early stage of viral infection and their roles in robust SARS-CoV-2 propagation,suggesting that EGFR is an attractive host target for combating COVID-19.

关键词： alterations aberrant thereby

Integral Formula of Minkowski Type and New Characterization of the Wulff Shape

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Acta Mathematica Sinica,English Series 2008年第4期24卷 697-704页

作者： yi jun HE Hai Zhong LI Department of Mathematical Sciences Tsinghua University Beijing 100084 P. R. China School of Mathematical Sciences Shanxi University Taiyuan 030006 P. R. China

Given a positive function F on S^n which satisfies a convexity condition, we introduce the r-th anisotropic mean curvature Mr for hypersurfaces in R^n＋1 which is a generalization of the usual r-th mean curvature Hr. We get integral formulas of Minkowski type for compact hypersurfaces in R^n＋1. We give some new characterizations of the Wulff shape by the use of our integral formulas of Minkowski type, in case F=1 which reduces to some well-known results.

关键词： Wulff shape F-Weingarten operator mean curvature integral formula of Minkowski type anisotropic principal curvature r-th anisotropic