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Statistically robust design of linear filter for non-regenerative MIMO relay systems

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The Journal of China Universities of Posts and Telecommunications 2011年第3期18卷 34-40页

作者： WANG Ying li gen GONG Feng Wireless Technology Innovation Institute Beijing University of Posts and Telecommunications Beijing 100876 China Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

This paper addresses the robust linear filter design issues for non-regenerative multiple input multiple output （MIMO） relay systems with imperfect channel state information （CSI） in both or partial hops. By considering statistical Kronecker channel model involving channel mean and antenna correlation, the robust linear processing schemes in imperfect CSI scenario for both hops are first derived based on mean squared error （MSE） criterion. In addition to this, the result is also extended to two practical scenarios, i.e. imperfect CSI for relay link with perfect CSI for access link and imperfect CSI for access link with perfect CSI for relay link. Simulation results show that the proposed scheme is capable of mitigating the performance degradation caused by the imperfect CSI.

关键词： MIMO relay linear filter robust design

Unsteady bio-fluid dynamics in flying and swimming

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Acta Mechanica Sinica 2017年第4期33卷 663-684页

作者： Hao liu Dmitry Kolomenskiy Toshiyuki Nakata gen li Graduate School of Engineering Chiba University 1-33Yayoi-cho Inage-ku Chiba Japan Shanghai-Jiao Tong University and Chiba UniversityInternational Cooperative Research Centre (SJTU-CU ICRC) Shanghai 200240 China

Flying and swimming in nature present sophisticated and exciting ventures in biomimetics, which seeks sustainable solutions and solves practical problems by emulating nature＇s time-tested patterns, functions, and strategies. Bio-fluids in insect and bird flight, as well as in fish swimming are highly dynamic and unsteady; however, they have been studied mostly with a focus on the phenomena associated with a body or wings moving in a steady flow. Characterized by unsteady wing flapping and body undulation, fluid-structure interactions, flexible wings and bodies, turbulent environments, and complex maneuver, bio-fluid dynamics normally have challenges associated with low Reynolds number regime and high unsteadiness in modeling and analysis of flow physics. In this article, we review and highlight recent advances in unsteady bio-fluid dynamics in terms of leading-edge vortices, passive mechanisms in flexible wings and hinges, flapping flight in unsteady environments, and micro-structured aerodynamics in flapping flight, as well as undulatory swimming, flapping-fin hydrodynamics, body–fin interac-tion, C-start and maneuvering, swimming in turbulence,collective swimming, and micro-structured hydrodynamics in swimming. We further give a perspective outlook on future challenges and tasks of several key issues of the field.

关键词： swimming wings unsteady turbulence hydrodynamics turbulent body kinematics vortex street

LARS韧带与自体腘绳肌腱加高强线保残重建后交叉韧带疗效比较

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中国骨伤 2024年第7期37卷 641-648页

作者：李根可雨奇杨梁大连医科大学附属第二医院辽宁大连116023

目的:比较关节镜下后交叉韧带(posterior cruciate ligament,PCL)保残重建术中应用先进韧带加强系统(ligament advanced reinforcement system,LARS)韧带与自体腘绳肌腱加高强线的临床效果。方法:选择2019年8月至2021年12月行关节镜下PCL保残重建术治疗的96例单纯PCL损伤,其中男78例,女18例;年龄20~56(32.50±8.68)岁;左侧40例,右侧56例。根据术中移植物不同分为两组。LARS韧带保残重建组(LARS韧带组)52例,其中男42例,女10例;年龄(31.84±8.62)岁;身体质量指数(body mass index,BMI)为(24.73±2.29)kg·m^(-2);采用7 mm LARS韧带保残重建PCL。自体腘绳肌腱加高强线组(自体肌腱组)44例,其中男36例,女8例;年龄(33.06±8.99)岁;BMI为(23.52±2.16)kg·m^(-2);采用4股腘绳肌腱加3根爱惜邦缝线加强技术保残重建PCL。术后3、6、12个月通过KT-1000测量膝关节的松弛度客观评价膝关节的稳定性,采用Lysholm、Tegner、国际膝关节文献委员会(International Knee Documentation Committee,IKDC)评分进行主观评分评价膝关节的功能。收集两组患者术前及术后3、6、12个月时随访的数据,比较两组患者术后康复情况及韧带松弛度的差异性。结果:96例患者获得随访,时间为12个月。膝关节KT-1000测量值自体肌腱组及LARS韧带组术前[(10.73±1.46)分vs(10.55±1.53)分]、术后6个月[(3.02±0.75)分vs(2.35±0.60)分]、12个月[(3.77±1.76)分vs(2.44±0.60)分],术后6、12个月组间比较差异有统计学意义(P0.05)。自体肌腱组、LARS韧带组术前及术后12个月Lysholm总分[(40.6±16.8)、(91.25±6.35)分vs(51.92±18.52)、(92.35±5.30)分],Tegner评分[(1.8±0.7)、(5.8±0.6)分vs(1.7±0.8)、(5.7±0.7)分],IKDC总分[(54.50±6.33)、(83.90±3.93)分vs(54.40±4.24)、(83.62±3.64)分],术后12个月与术前比较,差异均有统计学意义(P0.05)。结论:自体腘绳肌腱加高强线与LARS韧带保残重建PCL均可明显改善膝关节功能和稳定性,术后效果满意,但LARS韧带术后稳定性更佳。

关键词：后交叉韧带关节镜 LARS韧带自体肌腱高强线

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分布式光纤温度传感信号小波去噪方法

西安石油大学学报（自然科学版） 2024年第3期39卷 137-142页

作者：肖家悦傅海威陈苗李根程嘉慧西安石油大学陕西省油气资源光纤探测工程研究中心陕西省油气井测控技术重点实验室陕西西安710065

在分布式光纤拉曼温度传感系统中,反斯托克斯光包含了温度信息,但其强度相对较弱,易受到噪声干扰。传统的信号去噪方法往往会滤除系统所具有的原始特征。针对这一问题,本文提出了改进的小波阈值方法,将3sigm准则与传统算法相结合。在该... 详细信息

在分布式光纤拉曼温度传感系统中,反斯托克斯光包含了温度信息,但其强度相对较弱,易受到噪声干扰。传统的信号去噪方法往往会滤除系统所具有的原始特征。针对这一问题,本文提出了改进的小波阈值方法,将3sigm准则与传统算法相结合。在该算法中,对信号进行小波分解,再对分解的各层小波系数进行阈值处理,使用3sigm值来区分有用信号和噪声,然后进行小波重构,实现信号去噪。在7 km长的多模光纤上进行温度测量实验,使用改进的算法对数据进行分析。结果表明,改进的方法处理后的温度波动平均为0.991℃,相较于传统算法得到的2.422℃,提高了1.431℃。与传统算法相比,3sigm准则算法提高了测温精度,并为阈值的选择提供了新的思路,使阈值的选择更具统计意义。

关键词：分布式光纤传感测温精度小波阈值信号去噪

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红麻HcKAN4基因克隆、表达及在类黄酮合成中的功能

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作物学报 2024年第3期50卷 645-655页

作者：吴法轩李秦杨昕李新根徐建堂陶爱芬方平平祁建民张立武福建农林大学作物遗传育种与综合利用教育部重点实验室/农业农村部闽台作物生物育种重点实验室/福建省作物设计育种重点实验室福建福州350002 福建农林大学农业农村部东南黄红麻实验观测站/福建省麻类种质资源共享平台/福建省南方经济作物遗传育种与多用途开发国际科技合作基地福建福州350002

MYB类转录因子KAN4(KANADI4)在红麻类黄酮合成和纤维发育中发挥着重要作用。本研究以红麻品种‘福红952’为材料,对HcKAN4基因进行克隆和表达模式分析,探讨TRV-VIGS诱导该基因沉默对类黄酮合成途径中关键酶基因表达量改变的影响。基因... 详细信息

MYB类转录因子KAN4(KANADI4)在红麻类黄酮合成和纤维发育中发挥着重要作用。本研究以红麻品种‘福红952’为材料,对HcKAN4基因进行克隆和表达模式分析,探讨TRV-VIGS诱导该基因沉默对类黄酮合成途径中关键酶基因表达量改变的影响。基因克隆显示,HcKAN4基因开放阅读框(open reading frame,ORF)全长为966 bp,编码322个氨基酸,包含一个MYB保守结构域。进化树分析发现,其与拟南芥和木槿KAN4s的亲缘关系较近。表达分析表明,该基因在红麻不同组织中均有表达,且转录水平随着植物生长而递增。VIGS诱导基因沉默显示,6株HcKAN4的转录水平显著下调,达到基因沉默效果。进一步实时荧光定量PCR检测发现,类黄酮合成相关基因HcCHS、HcF3’5’H、HcANS、HcANR的转录水平显著下调,分别是对照组的0.51、0.14、0.23、0.11倍,表明HcKAN4基因可调控红麻类黄酮生物合成相关基因。这些结果为阐明红麻MYB转录因子调控类黄酮合成提供了依据,同时为改善纤维品质提供了研究思路。

关键词：红麻 HcKAN4 类黄酮合成 VIGS

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混合动力电动汽车构型优化设计方法研究

兰州理工大学学报 2024年第1期50卷 60-67页

作者：赵斯力根王静远张晓明承德应用技术职业学院汽车工程系河北承德067000 河北红星汽车制造有限公司河北邢台675808

针对行星齿轮汽车结构特性与动态特性的关系,提出了混合动力汽车动力系统构型的理论设计方法.首先,将构型中所有连接分为3类,采用矩阵表示法表示这些连接,以反映系统动力学和构型的物理结构.接着,在此基础上提出了构型自动设计的矩阵表... 详细信息

针对行星齿轮汽车结构特性与动态特性的关系,提出了混合动力汽车动力系统构型的理论设计方法.首先,将构型中所有连接分为3类,采用矩阵表示法表示这些连接,以反映系统动力学和构型的物理结构.接着,在此基础上提出了构型自动设计的矩阵表示方法,通过矩阵运算得到转速方程进而得到汽车双行星齿轮结构的各种构型.最后,通过仿真验证了该方法的有效性.结果表明,在矩阵表示方法的支持下,可以通过计算机自动完成最优构型的选择,避免了人工计算和比较,节省了大量的精力和时间.

关键词：混合动力汽车行星齿轮组动力构型设计方法

Aeolian activity in the southern Gurbantunggut Desert of China during the last 900 years

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Journal of Arid Land 2023年第6期15卷 649-666页

作者： li Wen MU Guijin YE Changsheng XU lishuai li gen Key Laboratory for Digital Land and Resources of Jiangxi Province East China University of TechnologyNanchang 330013China School of Earth Sciences East China University of TechnologyNanchang 330013China Xinjiang Institute of Ecology and Geography Chinese Academy of SciencesUrumqi 830011China College of Resources and Environment Shanxi Agricultural UniversityJinzhong 030801China

The mineral dust emitted from Central Asia has a significant influence on the global climate ***,the history and mechanisms of aeolian activity in Central Asia remain unclear,due to the lack of well-dated records of aeolian activity and the intense wind erosion in some of the dust source areas(e.g.,deserts).Here,we present the records of aeolian activity from a sedimentary sequence in the southern Gurbantunggut Desert of China using grain size analysis and optically stimulated luminescence(OSL)dating,based on field sampling in ***,we used eight OSL dates to construct chronological frameworks and applied the end-member(EM)analysis for the grain size data to extract the information of aeolian activity in the southern Gurbantunggut Desert during the last 900 *** results show that the grain size dataset can be subdivided into three EMs(EM1,EM2,and EM3).The primary modal sizes of these EMs(EM1,EM2,and EM3)are 126.00,178.00,and 283.00μm,***1 represents a mixture of the suspension components and saltation dust,while EM2 and EM3 show saltation dust transported over a shorter distance via strengthened near-surface winds,which can be used to trace aeolian *** with the OSL chronology,our results demonstrate that during the last 900 a,more intensive and frequent aeolian activity occurred during 450-100 a BP(Before Present)(i.e.,the little Ice Age(liA)),which was reflected by a higher proportion of the coarse-grained components(EM2+EM3).Aeolian activity decreased during 900-450 a BP(i.e.,the Medieval Warm Period(MWP))and 100 a BP-present(i.e.,the Current Warm Period(CWP)).Intensified aeolian activity was associated with the strengthening of the Siberian High and cooling events at high northern *** propose that the Siberian High,under the influence of temperature changes at high northern latitudes,controlled the frequency and intensity of aeolian activity in Central *** at high northern latitudes would have si

关键词： aeolian activity grain size wind regime little Ice Age Siberian High climatic drying Central Asia

Untrusted Hardware Causes Double-Fetch Problems in the I/O Memory

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Journal of Computer Science & Technology 2018年第3期33卷 587-602页

作者： Kai Lu Peng-Fei Wang gen li Xu Zhou College of Computer National University of Defense Technology Changsha 410073 China Science and Technology on Parallel and Distributed Processing Laboratory National University of Defense Technology Changsha 410073 China Collaborative Innovation Center of High-Performance Computing National University of Defense Technology Changsha 410073 China

The double fetch problem occurs when the data is maliciously changed between two kernel reads of the supposedly same data, which can cause serious security problems in the kernel. Previous research focused on the double fetches between the kernel and user applications. In this paper, we present the first dedicated study of the double fetch problem between the kernel and peripheral devices （aka. the hardware double fetch）. Operating systems communicate with peripheral devices by reading from and writing to the device mapped I/O （input and output） memory. Owing to the lack of effective validation of the attached hardware, compromised hardware could flip the data between two reads of the same I/O memory address, causing a double fetch problem. We propose a static pattern-matching approach to identify the hardware double fetches from the linux kernel. Our approach can analyze the entire kernel without relying on the corresponding hardware. The results are categorized and each category is analyzed using case studies to discuss the possibility of causing bugs. We also find four previously unknown double-fetch vulnerabilities, which have been confirmed and fixed after reporting them to the maintainers.

关键词： hardware double fetch double-fetch bug I/O memory peripheral device double-fetch vulnerability

Coordinated Control of DC Circuit Breakers in Multilink HVDC Grids

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CSEE Journal of Power and Energy Systems 2023年第6期9卷 2224-2235页

作者： Xibei Zhao Jianzhong Xu gen li Jinsha Yuan Jun liang the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 100096China the Technical University of Denmark Denmark the School of Engineering Cardiff UniversityUK.

High voltage DC grids are developing in more terminals and with larger transmission capacity,thus the re-quirements for DC circuit breakers(DCCB)will continue to *** methods only use the faulty line DCCB to withstand the fault stress,and therefore this paper presents a coordination method of multiple DCCBs to protect the *** many adjacent DCCBs are tripped to interrupt the fault current,the fault energy is shared,and the requirement for the faulty line DCCB is ***,the adjacent DCCBs are actively controlled to help system *** primary protection,backup protection,and reclosing logic of multiple DCCBs are *** confirm that the proposed control reduces the energy dissipation requirement of faulty line DCCB by approximately 30%-42%,the required current rating for IGBTs is reduced,and the system recovery time is also reduced by 20-40 ms.

关键词： DC circuit breakers(DCCB) DC fault DC grid DC protection fault current limiting