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Expansion and expression diversity of FAR1/FRS-like genes provides insights into flowering time regulation in roses 被引量:1
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作者 Mi-Cai Zhong Xiao-Dong Jiang +1 位作者 Wei-Hua Cui Jin-Yong Hu 《Plant Diversity》 SCIE CAS CSCD 2021年第2期173-179,共7页
Roses are important horticultural plants with enormous diversity in flowers and flowering behavior.However,molecular regulation of flowering time variation in roses remains poorly characterized.Here,we report an expan... Roses are important horticultural plants with enormous diversity in flowers and flowering behavior.However,molecular regulation of flowering time variation in roses remains poorly characterized.Here,we report an expansion of the FAR1/FRS-like genes that correlates well with the switch to prostrate-toerect growth of shoots upon flowering in Rosa wichuraiana‘Basye's Thornless'(BT).With the availability of the high-quality chromosome-level genome assembly for BT that we developed recently,we identified 91 RwFAR1/FRS-like genes,a significant expansion in contrast to 52 in Rosa chinensis‘Old Blush’(OB),a founder genotype in modern rose domestication.Rose FAR1/FRS-like proteins feature distinct variation in protein domain structures.The dispersed expansion of RwFAR1/FRS-like genes occurred specifically in clade I and II and is significantly associated with transposon insertion in BT.Most of the RwFAR1/FRS-like genes showed relatively higher expression level than their corresponding orthologs in OB.FAR1/FRS-like genes regulate light-signaling processes,shade avoidance,and flowering time in Arabidopsis thaliana.Therefore,the expansion and duplication of RwFAR1/FRS-like genes,followed by diversification in gene expression,might offer a novel leverage point for further understanding the molecular regulation of the variation in shoot-growth behavior and flowering time in roses. 展开更多
关键词 ROSE FAR1/FRS-Like genes Gene family expansion Flowering time Shoot growth behavior
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Nonlinear Time-Varying Systems Identification Using Basis Sequence Expansions Combined with Neural Networks
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作者 顾成奎 王正欧 孙雅明 《Transactions of Tianjin University》 EI CAS 2003年第1期71-74,共4页
A new method for identifying nonlinear time varying systems with unknown structure is presented. The method extends the application area of basis sequence identification. The essential idea is to utilize the learning ... A new method for identifying nonlinear time varying systems with unknown structure is presented. The method extends the application area of basis sequence identification. The essential idea is to utilize the learning and nonlinear approximating ability of neural networks to model the non linearity of the system, characterize time varying dynamics of the system by the time varying parametric vector of the network, then the parametric vector of the network is approximated by a weighted sum of known basis sequences. Because of black box modeling ability of neural networks, the presented method can identify nonlinear time varying systems with unknown structure. In order to improve the real time capability of the algorithm, the neural network is trained by a simple fast learning algorithm based on local least squares presented by the authors. The effectiveness and the performance of the method are demonstrated by some simulation results. 展开更多
关键词 nonlinear time varying systems IDENTIFICATION basis sequence expansions neural networks
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Pinched Material Einstein Space-Time Produces Accelerated Cosmic Expansion
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作者 M. S. El Naschie 《International Journal of Astronomy and Astrophysics》 2014年第1期80-90,共11页
An instructive analogy between the deformation of a pinched elastic cylindrical shell and the anti-gravity behind accelerated cosmic expansion is established. Subsequently the entire model is interpreted in terms of a... An instructive analogy between the deformation of a pinched elastic cylindrical shell and the anti-gravity behind accelerated cosmic expansion is established. Subsequently the entire model is interpreted in terms of a hyperbolic fractal Rindler space-time leading to the same robust results regarding real energy and dark energy being 4.5% and 95.5% respectively in full agreement with all recent cosmological measurements. 展开更多
关键词 Dark Energy Rindler SPACE-time CARTAN Torsion Pinched Elastic Shells Negative Gravity COSMIC ACCELERATED expansion Fractal SPACE-time Topological Defects Hardy’s Quantum Entanglement Hawking’s Radiation COSSERAT Elasticity
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基于TimeGAN和LightGBM的多维时间序列故障样本扩充与诊断研究 被引量:1
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作者 马良玉 翟亮亮 韩立凯 《电力科学与工程》 2025年第9期13-21,共9页
火电机组热力系统故障往往会经历从轻微到严重的发展过程,而轻度和早期故障因特征不明显很容易被漏诊,这将导致故障进一步发展带来更严重的后果。鉴于机组实际运行中故障样本较为稀缺且记录的多为特征明显的中、重度故障样本,为提高轻... 火电机组热力系统故障往往会经历从轻微到严重的发展过程,而轻度和早期故障因特征不明显很容易被漏诊,这将导致故障进一步发展带来更严重的后果。鉴于机组实际运行中故障样本较为稀缺且记录的多为特征明显的中、重度故障样本,为提高轻度故障诊断的及时性和准确率,提出一种基于时间对抗生成网络(Time-series generative adversarial networks, Time GAN)和轻量级梯度提升机(Light gradient boosting machine, LightGBM)的多维时间序列故障样本扩充及故障诊断方法。数据方面,利用Time GAN对已有的中、重度故障数据进行扩充,生成反映真实故障样本分布且更具多样性的故障样本;模型方面,基于扩充后的故障样本集,采用贝叶斯寻优的LightGBM算法建立故障分类模型,以提高轻度和早期故障的识别能力。以600 MW火电机组高压加热器系统故障诊断为例开展实验研究,结果表明所提方法对轻微故障的诊断效果明显改善,验证了故障样本扩充和诊断方法的有效性。 展开更多
关键词 火电机组 故障诊断 多维时间序列 样本扩充 时间对抗生成网络 轻量级梯度提升机
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Exact solutions of nonlinear fractional differential equations by (G'/G)-expansion method 被引量:6
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作者 Ahmet Bekir zkan Güner 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第11期140-145,共6页
In this paper, we use the fractional complex transform and the (G'/G)-expansion method to study the nonlinear fractional differential equations and find the exact solutions. The fractional complex transform is prop... In this paper, we use the fractional complex transform and the (G'/G)-expansion method to study the nonlinear fractional differential equations and find the exact solutions. The fractional complex transform is proposed to convert a partial fractional differential equation with Jumarie's modified Riemann-Liouville derivative into its ordinary differential equation. It is shown that the considered transform and method are very efficient and powerful in solving wide classes of nonlinear fractional order equations. 展开更多
关键词 (G'/G)-expansion method time-fractional Burgers equation fractional-order biological popula-tion model space-time fractional Whitham-Broer-Kaup equations
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Marginal Expansion Planning of Infrastructure at a Container Terminal
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作者 Keng Bin Loke Ab. Saman Abd. Kader +2 位作者 Mohd. Zamani Ahmad Saharuddin Abdul Hamid Mohamad Rosni Othman 《Open Journal of Marine Science》 2015年第1期99-107,共9页
Globalization push container terminal grown rapidly in decade. To fulfill the future traffic requirement, this study highlights marginal expansion planning of infrastructure in a container terminal. By using marginal ... Globalization push container terminal grown rapidly in decade. To fulfill the future traffic requirement, this study highlights marginal expansion planning of infrastructure in a container terminal. By using marginal approach, the expansion plan can be determine correctly and economically stage by stage. A mathematical model has generated to calculate the expansion size, expansion time, interval of expansion, expansion cost, and significant of expansion for each infrastructure respectively. It recommended determining the expansion plan for each infrastructure respectively. This is because one of the infrastructures needs to be expanding but the other may not. The generated model was verified with others model and validated with case study to investigate the practicability of the model. The model serves as expansion decision making tools to assist port expansion planners. 展开更多
关键词 INFRASTRUCTURE MARGINAL Approach expansion PLAN MATHEMATICAL Model expansion SIZE expansion time
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Quinoa Expansion in Peruvian Departments and Land Use Change before the Health Crisis
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作者 Jhon Huillca Baldomero Segura Aquilino Álvarez 《Agricultural Sciences》 2021年第8期827-843,共17页
National and international policies have promoted quinoa consumption, influencing the expansion of the crop, and generating changes in land use. In this article, we analyzed the evolution of quinoa cultivation in Peru... National and international policies have promoted quinoa consumption, influencing the expansion of the crop, and generating changes in land use. In this article, we analyzed the evolution of quinoa cultivation in Peru both at the national and departmental levels. Time series analysis vas used to. Between 1951 and 2019, the evolution of the quinoa-harvested areas in Peru has gone through various stages, first in regression until 1990, and then it has experienced a growth rate of 10%. Puno is still by far the department where the crop is most widespread. Taking into account the geographical and technological conditions, this highland area is less likely to maintain the rate of expansion than the Peruvian coast, which will imply great challenges for Andean farmers who have maintained the traditional crop throughout the period. 展开更多
关键词 QUINOA Land Use expansion Rate time Series Traditional Zones
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Why the Expansion of the Universe Appears to Accelerate
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作者 Paul Smeulders 《Journal of Modern Physics》 2013年第6期780-783,共4页
A Speed of Light falling over time inversely proportional to the expansion of the Universe leads to an experimentally observed exponential changing of the Red Shift over time. It is necessary to re-define the Angular ... A Speed of Light falling over time inversely proportional to the expansion of the Universe leads to an experimentally observed exponential changing of the Red Shift over time. It is necessary to re-define the Angular Impulse Momentum in order to get a consistent expansion of space on all levels. Conservation of Energy and this newly defined Angular Impulse Momentum then leads to the requirement that all clocks slow down in time inversely proportional to the Red Shift, independent of whether the Speed of Light is constant or not. From the Lorentz equation it then follows that Expansion occurs over space-time and not over space alone. A steady state expansion in true time is then transformed into an exponential expansion for an observer with a local clock. A finite lifetime of the Universe is transformed to an infinite lifetime for these observers including elementary particles. 展开更多
关键词 Acceleration of expansion expansion of SPACE-time EXPONENTIAL expansion Conservation LAWS DARK Energy
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Accelerated Expansion of Space, Dark Matter, Dark Energy and Big Bang Processes
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作者 Auguste Meessen 《Journal of Modern Physics》 2017年第2期251-267,共17页
The accelerated expansion of our universe results from properties of dark matter particles deduced from Space-Time Quantization. This theory accounts for all possible elementary particles by considering a quantum of l... The accelerated expansion of our universe results from properties of dark matter particles deduced from Space-Time Quantization. This theory accounts for all possible elementary particles by considering a quantum of length a in addition to c and h. It appears that dark matter particles allow for fusion and fission processes. The resulting equilibrium enables the cosmic dark matter gas to produce dark energy in an adaptive way. It keeps the combined matter-energy density at a constant level, even when space is expanding. This accounts for the cosmological constant &Lambda;and the accelerated expansion of space without requiring any negative pressure. The Big Bang is related to G, c, h and a. It started with a “primeval photon” and led to the cosmic matter-antimatter asymmetry as well as inflation. 展开更多
关键词 Accelerated expansion DARK MATTER DARK Energy SPACE-time Quantization Big Bang INFLATION Matter-Antimatter Asymmetry
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Time Definition Using the Extrinsic Universe: Expanding the Big Bang Theory
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作者 Yuri Nunes Silva 《Journal of High Energy Physics, Gravitation and Cosmology》 2025年第1期168-182,共15页
This paper aims to define the concept of time and justify its properties within the universal context, shedding new light on the nature of time. By employing the concept of the extrinsic universe, the paper explains t... This paper aims to define the concept of time and justify its properties within the universal context, shedding new light on the nature of time. By employing the concept of the extrinsic universe, the paper explains the observable universe as the three-dimensional surface of a four-dimensional 3-sphere (hypersphere), expanding at the speed of light. This expansion process gives rise to what we perceive as time and its associated aspects, providing a novel interpretation of time as a geometric property emerging from the dynamics of the universe’s expansion. The work offers insights into how this extrinsic perspective can address phenomena such as the universe’s accelerated expansion and dark matter, aligning the model with current observational data. 展开更多
关键词 Extrinsic Universe time: Origin and Nature Cosmology: Universe expansion Dark Energy and Dark Matter
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青岛市城镇空间扩展及驱动力研究
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作者 刘兆德 李沅泽 +1 位作者 刘文奇 闫怡然 《国土与自然资源研究》 2026年第1期1-5,共5页
借助Arc GIS,提取青岛市4个年份的城镇用地,通过土地利用转移矩阵、城镇扩展强度指数、等扇形分析法和主成份分析等方法,研究青岛市1990年以来的城镇空间扩展的时空特征及驱动力。结果表明,(1)青岛市土地利用相互转化情况最为剧烈的为... 借助Arc GIS,提取青岛市4个年份的城镇用地,通过土地利用转移矩阵、城镇扩展强度指数、等扇形分析法和主成份分析等方法,研究青岛市1990年以来的城镇空间扩展的时空特征及驱动力。结果表明,(1)青岛市土地利用相互转化情况最为剧烈的为耕地以及城镇用地,城镇用地转入面积远大于转出面积,城镇用地面积大幅度增加。(2)青岛城镇用地扩展面积和扩展强度的变化趋势保持一致,呈现出先增长后下降的趋势,城镇空间的高速扩展阶段为2000-2010年。(3)受东部山区、市内4区发展空间有限等条件的制约以及经济重心的西移,青岛城镇用地长期以东北-西南条带状扩展为主,扩展模式上以边缘式扩展为主。(4)经济发展水平、人口和产业集聚能力以及经济全球化水平是驱动青岛市城镇空间扩展的重要因素。 展开更多
关键词 城镇空间扩展 时空变化 驱动力 青岛市
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TimeGAN-Informer长时机场能见度预测 被引量:5
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作者 马愈昭 张宇航 王凌飞 《安全与环境学报》 CAS CSCD 北大核心 2024年第7期2517-2527,共11页
能见度的预测对机场的业务决策、保障飞机的安全起降具有重要的意义。针对现有能见度预测模型预测时间较短的问题,提出一种基于TimeGAN Informer(Time Generative Adversarial Network-Informer)的机场能见度预测方法。利用2018—2022... 能见度的预测对机场的业务决策、保障飞机的安全起降具有重要的意义。针对现有能见度预测模型预测时间较短的问题,提出一种基于TimeGAN Informer(Time Generative Adversarial Network-Informer)的机场能见度预测方法。利用2018—2022年气象和污染物数据,通过相关系数法和递归特征消除法提取出能见度的主要影响因素,使用TimeGAN时间序列生成对抗网络对数据进行扩充,并将Informer长时间序列预测模型应用于能见度预测。结果显示:当预测步长为1 d、2 d、3 d时,TimeGAN Informer的绝对误差(Mean Absolute Error,MAE)分别为2.42、3.13、3.57,比Informer分别降低了0.29、0.27、0.28,比长短时记忆网络(Long Short-Term Memory,LSTM)分别降低了0.28、0.49、0.63;均方根误差(Root Mean Square Error,RMSE)分别为3.03、3.7、4.09,比Informer分别降低了0.38、0.22、0.24,比长短时记忆网络(LSTM)分别降低了0.3、0.5、1.04;百分误差小于30%的分别占测试样本集的78.07%、70.68%、63.84%。尽管随着步长的增加预测效果变差,但在预测步长为3 d时,多数样本的预测误差仍小于30%,实现了对机场区域较为准确的长时能见度预测。 展开更多
关键词 安全工程 能见度预报 数据扩充 INFORMER 时间序列
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掺膨胀剂水泥基材料收缩时变规律及机理研究
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作者 薛翠真 王宁 +1 位作者 乔宏霞 苏丽 《华中科技大学学报(自然科学版)》 北大核心 2026年第2期92-100,共9页
为解决水泥基材料因收缩变形而导致建筑结构开裂的问题,在研究膨胀剂种类及掺量对水泥基材料干燥收缩时变影响规律的基础上,揭示膨胀剂种类及掺量对水泥基材料孔隙结构、水化产物及微观形貌的影响规律,结合试件干燥收缩时变规律阐明膨... 为解决水泥基材料因收缩变形而导致建筑结构开裂的问题,在研究膨胀剂种类及掺量对水泥基材料干燥收缩时变影响规律的基础上,揭示膨胀剂种类及掺量对水泥基材料孔隙结构、水化产物及微观形貌的影响规律,结合试件干燥收缩时变规律阐明膨胀剂对水泥基材料干燥收缩性能的影响机理.试验结果表明:膨胀剂的掺入降低了水泥基材料的干燥收缩率,可有效补偿水泥基材料的干燥收缩;MgO膨胀剂对于提升试件抵抗干燥收缩变形的效果最佳,其次为双膨胀源膨胀剂,最次为H型膨胀剂;MgO膨胀剂、H型膨胀剂、双膨胀源膨胀剂最佳掺量分别为6%,8%和6%.不同种类膨胀剂收缩发展速度由大到小分别为:MgO膨胀剂>双膨胀源膨胀剂>H型膨胀剂.膨胀剂主要通过影响水泥基材料水化产物种类及数量、微观形貌及孔结构,进而影响其抗干缩性能.膨胀剂的掺入使水泥砂浆内部片状晶体氢氧化镁、氢氧化钙、AFt等晶体含量增多.不同种类膨胀剂均提高了水泥砂浆内部密实度,降低了试件总孔隙,宏观上表现为膨胀剂的掺入对试件收缩性能起到了积极作用.研究结果为实际工程中减小水泥混凝土的干燥收缩开裂提供了一定的理论参考. 展开更多
关键词 膨胀剂 水泥基材料 干燥收缩 时变规律 孔结构 微观形貌 影响机理
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一次性13 mm固定通道下MIS-TLIF治疗腰椎间盘突出症的对比研究
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作者 顾佳龙 赵敏 +5 位作者 肖波 蔡晓敏 肖春林 杨俊 李浩 周江军 《生物骨科材料与临床研究》 2026年第2期34-39,共6页
目的比较一次性13 mm固定通道与Quadrant扩张通道下微创经椎间孔入路腰椎椎间融合(minimally invasive transforaminal lumbar interbody fusion,MIS-TLIF)治疗腰椎间盘突出症手术效果。方法回顾性研究2022年7月至2023年7月在中国人民... 目的比较一次性13 mm固定通道与Quadrant扩张通道下微创经椎间孔入路腰椎椎间融合(minimally invasive transforaminal lumbar interbody fusion,MIS-TLIF)治疗腰椎间盘突出症手术效果。方法回顾性研究2022年7月至2023年7月在中国人民解放军联勤保障部队第九〇八医院住院的腰椎间盘突出症37例患者,采用两种方式进行MIS-TLIF手术治疗,13 mm通道组20例,Quadrant通道组17例。统计两组患者的手术时间、术中出血量、切口长度、住院时间,以及腰腿痛VAS评分、JOA及ODI评分等随访指标进行对比研究。结果所有患者均获得了完整随访,随访时间为12~16个月,平均(13.81±1.45)个月。在术中出血量、切口长度、手术时间等方面13 mm通道组要优于Quadrant通道组(P<0.05),但在住院时间方面两组之间比较差异无统计学意义(P>0.05)。两组患者术后3 d、1个月、3个月、12个月的腰腿痛VAS评分、JOA及ODI评分均较术前明显下降(P<0.05),但两组之间比较差异无统计学意义(P>0.05)。结论一次性13 mm固定通道与Quadrant扩张通道对腰椎间盘突出症的疗效相当,均取得了良好的临床疗效。同时一次性13 mm固定通道具有可透视、创伤小、出血少、术中肌肉组织阻挡较好、术后疼痛轻等优点,相较于传统扩张通道更值得推广。 展开更多
关键词 腰椎间盘突出症 通道下经椎间孔入路腰椎椎间融合术 一次性13 mm固定通道 Quadrant扩张通道
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不同温度条件下镁质膨胀源的砂浆线性膨胀率规律研究
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作者 李丽 赵珏 +4 位作者 戈兵 边学俊 马郁 尹航 孙俊 《新型建筑材料》 2026年第2期16-19,共4页
基于不同温度及氧化镁掺量下砂浆线性膨胀率的实测数据,建立了不同温度条件下砂浆线性膨胀率的双曲线预测模型。通过化学反应动力学理论和模型拟合回归分析,确定了砂浆试件的反应速率常数与最终线性膨胀率,并结合Arrhenius方程建立了反... 基于不同温度及氧化镁掺量下砂浆线性膨胀率的实测数据,建立了不同温度条件下砂浆线性膨胀率的双曲线预测模型。通过化学反应动力学理论和模型拟合回归分析,确定了砂浆试件的反应速率常数与最终线性膨胀率,并结合Arrhenius方程建立了反应速率常数与温度的关系式,进而利用成熟函数推导出等效时间。最终,研究通过快速养护法实现了常温下含镁质膨胀源的砂浆线性膨胀率预测模型的建立,并验证了该预测模型的可行性和准确性,可为实际工程中掺镁质膨胀源砂浆的线性膨胀率预测提供参考,同时为评价氧化镁对砂浆体积稳定性的潜在危害程度提供技术支撑。 展开更多
关键词 镁质膨胀源 砂浆线性膨胀率 Arrhenius方程 等效时间
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基于到达时间差与频率差量测无偏转换的辐射源跟踪算法
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作者 谢欣辰 高林 +1 位作者 魏平 李万春 《系统工程与电子技术》 北大核心 2026年第3期751-757,共7页
由于单通道接收机量测与辐射源状态之间的非线性关系,利用到达时间差(time difference of arrival,TDOA)和到达频率差(frequency difference of arrival,FDOA)量测进行远距离跟踪变得具有挑战性,导致状态估计在二阶矩上产生偏差。为解... 由于单通道接收机量测与辐射源状态之间的非线性关系,利用到达时间差(time difference of arrival,TDOA)和到达频率差(frequency difference of arrival,FDOA)量测进行远距离跟踪变得具有挑战性,导致状态估计在二阶矩上产生偏差。为解决该问题,提出基于量测转换的算法。利用二阶泰勒展开逼近非线性观测方程,进而将TDOA/FDOA量测转换到辐射源状态空间。同时,在二阶泰勒逼近的程度上实现量测协方差转换,尽可能减少转换过程中带来的偏差。仿真结果表明,所提算法相对于一阶泰勒展开近似的量测转换以及无迹卡尔曼滤波器具有更高的辐射源跟踪精度,且计算量与无迹卡尔曼滤波器相近。因此,所提方法具有广阔的应用前景。 展开更多
关键词 到达时间差 到达频率差 无偏量测转换卡尔曼滤波 二阶泰勒展开
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改扩建路基结合部典型病害的地震波传播特征分析
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作者 荣耀 刘金枝 《重庆科技大学学报(自然科学版)》 2026年第1期50-59,共10页
改扩建路基结合部病害的精准识别对保障道路安全运营至关重要。基于地震波法构建含空洞、裂隙和不密实等典型病害的二维数值模型,分析不同位置、不同类型病害对地震波传播特性的影响,并在模型表面布设了多个检波器,通过获取的数据进行... 改扩建路基结合部病害的精准识别对保障道路安全运营至关重要。基于地震波法构建含空洞、裂隙和不密实等典型病害的二维数值模型,分析不同位置、不同类型病害对地震波传播特性的影响,并在模型表面布设了多个检波器,通过获取的数据进行时域、频谱与时频分析。研究结果表明:不同位置、不同类型的病害对地震波传播具有显著影响,其中,浅层病害及长条空洞、圆形空洞、裂隙病害引起的波场扰动最为强烈,可识别性更高;深层病害与矩形空洞、不密实病害因尺度有限,扰动特征不明显,识别难度较大。多维特征提取方法可有效揭示病害干扰的时频演化规律。 展开更多
关键词 改扩建路基 地震波 数值模拟 时频分析
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ON COLLISION LOCAL TIME OF TWO INDEPENDENT FRACTIONAL ORNSTEIN-UHLENBECK PROCESSES 被引量:2
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作者 郭精军 李楚进 《Acta Mathematica Scientia》 SCIE CSCD 2017年第2期316-328,共13页
In this article, we study the existence of collision local time of two indepen- dent d-dimensional fractional Ornstein-Uhlenbeck processes X+^H1 and Xt^H2 with different parameters Hi ∈ (0, 1),i = 1, 2. Under the ... In this article, we study the existence of collision local time of two indepen- dent d-dimensional fractional Ornstein-Uhlenbeck processes X+^H1 and Xt^H2 with different parameters Hi ∈ (0, 1),i = 1, 2. Under the canonical framework of white noise analysis, we characterize the collision local time as a Hida distribution and obtain its' chaos expansion. Key words Collision local time; fractional Ornstein-Uhlenbeck processes; generalized white noise functionals; choas expansion 展开更多
关键词 Collision local time fractional Ornstein-Uhlenbeck processes generalized white noise functionals choas expansion
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Exploring the Evolution of Passenger Flow and Travel Time Reliability with the Expanding Process of Metro System Using Smartcard Data 被引量:1
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作者 Xinwei Ma Yanjie Ji +1 位作者 Yao Fan Chenyu Yi 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2019年第1期17-29,共13页
Metro system has experienced the global rapid rise over the past decades. However,few studies have paid attention to the evolution in system usage with the network expanding. The paper's main objectives are to ana... Metro system has experienced the global rapid rise over the past decades. However,few studies have paid attention to the evolution in system usage with the network expanding. The paper's main objectives are to analyze passenger flow characteristics and evaluate travel time reliability for the Nanjing Metro network by visualizing the smart card data of April 2014,April 2015 and April 2016. We performed visualization techniques and comparative analyses to examine the changes in system usage between before and after the system expansion. Specifically,workdays,holidays and weekends were specially segmented for analysis.Results showed that workdays had obvious morning and evening peak hours due to daily commuting,while no obvious peak hours existed in weekends and holidays and the daily traffic was evenly distributed. Besides,some metro stations had a serious directional imbalance,especially during the morning and evening peak hours of workdays. Serious unreliability occurred in morning peaks on workdays and the reliability of new lines was relatively low,meanwhile,new stations had negative effects on exiting stations in terms of reliability. Monitoring the evolution of system usage over years enables the identification of system performance and can serve as an input for improving the metro system quality. 展开更多
关键词 METRO expansion smart CARD DATA PASSENGER flow characteristics TRAVEL time reliability visualization
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Rock Breakage Using Expansive Cement 被引量:1
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作者 Amr El Dessouki Hani Mitri 《Engineering(科研)》 2011年第2期168-173,共6页
Expansive cements are powdery materials which produce expansive stresses during the moist curing process. These cements are classified as shrinkage-compensated or self-stressing cements. The shrinkage compensated is u... Expansive cements are powdery materials which produce expansive stresses during the moist curing process. These cements are classified as shrinkage-compensated or self-stressing cements. The shrinkage compensated is used in the construction industry and will not be investigated in this paper. Self-Stressing cement is widely used in the demolition & fragmentation industry and will be the main focus of this report. The objective of this paper is to discuss the relationship between Sulfate-compounds on the expansion time and degree of expansion of Betonamit expansive cement. Based on literature [1], expansion time is directly proportional to sulfate content when mixed with Portland cement. Hence, as the sulfate content of the cement mixture increases, expansion time increases. However, in this research project the effect of Portland cement was removed to further examine the effect of sulfate on Betonamit only. This phenomenon was investigated using various concentrations of 4 different Sulfate-compounds. The results proved the possibility of decreasing the expansion time of Betonamit and, quite remarkably, a much greater degree of expansion was obtained. 展开更多
关键词 expansive CEMENT Betonamit Sulphate-Compounds expansion time DEGREE of expansion
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