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双深度Warping变换的浅海近水面声源被动测距
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作者 陈孟奇 郭良浩 +1 位作者 刘建军 张灵珊 《声学学报》 北大核心 2025年第5期1079-1094,共16页
在浅海水声环境中, Warping变换可在频域分离相干分量,但被动测距需辨识特征频率峰的模态阶数。由于负跃层条件下低阶简正波衰减严重,增加了模态判别难度。为此,提出了一种双深度Warping变换方法,在垂直双水听器的接收条件下,将两个深... 在浅海水声环境中, Warping变换可在频域分离相干分量,但被动测距需辨识特征频率峰的模态阶数。由于负跃层条件下低阶简正波衰减严重,增加了模态判别难度。为此,提出了一种双深度Warping变换方法,在垂直双水听器的接收条件下,将两个深度处自相关函数Warping变换差异结合互相关函数Warping变换对模态阶数信息进行筛选,可降低被动测距的模糊问题。同时,通过分割信号处理频带,组合宽频带和窄频带的特征频率信息,可有效提升被动测距的性能。当双接收深度的声场相干分量垂直相关系数较低时,两个深度的自相关函数Warping变换主特征频率峰位置差异较大,此时被动测距方法的性能较好;双接收深度的垂直相关系数较高时,可引起测距性能下降。仿真结果和试验数据处理结果均验证了所提方法的有效性。 展开更多
关键词 Warping变换 互相关函数 垂直双水听器 测距模糊 模态判别
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基于SAT的WARP算法的代数攻击
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作者 郝春雨 徐洪 《密码学报(中英文)》 北大核心 2025年第2期283-296,共14页
WARP算法是由Banik等人在SAC2020会议上提出的一种轻量级分组密码算法,具有极低的硬件成本,可以作为AES-128算法的轻量级代替.本文基于SAT方法研究了对WARP算法的代数攻击,在代数攻击模型的构建上,提出WARP算法线性运算和非线性运算的... WARP算法是由Banik等人在SAC2020会议上提出的一种轻量级分组密码算法,具有极低的硬件成本,可以作为AES-128算法的轻量级代替.本文基于SAT方法研究了对WARP算法的代数攻击,在代数攻击模型的构建上,提出WARP算法线性运算和非线性运算的不同建模方式,并根据SAT模型的特点,利用多种预处理技术简化模型,提高求解效率.在求解SAT模型时,分析了当密钥变元重量、明密文对数和密钥穷举量不同时相应SAT模型的求解效率.利用这些方法,通过穷举40比特密钥,使用60对具有差分结构的明密文进行代数攻击,在约2^(53.28) s内,可以恢复15轮WARP算法的全部128比特密钥. 展开更多
关键词 WARP 轻量级分组密码 代数攻击 SAT
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基于warping变换波数谱的运动声源速度估计方法研究
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作者 谢世伟 徐铭 +1 位作者 袁笑 苟欣迪 《海洋湖沼通报(中英文)》 北大核心 2025年第3期90-97,共8页
当接收器静止,声源保持同一深度沿直线匀速运动时,频域上接收到的声压信号相位随时间呈非线性变化,运用warping变换可以实现相位线性化,以此提出一种利用该变换估计声源运动参数的算法。首先构造不同运动参数下的warping算子,再利用算... 当接收器静止,声源保持同一深度沿直线匀速运动时,频域上接收到的声压信号相位随时间呈非线性变化,运用warping变换可以实现相位线性化,以此提出一种利用该变换估计声源运动参数的算法。首先构造不同运动参数下的warping算子,再利用算子对接收到的频域声压进行重采样,最后对重采样后的声压进行傅里叶变换得到相应的波数谱;据此,可以利用特定区间波数谱能量最大来实现声源速度估计,另外,在低信噪比条件下,讨论了一种基于速度-波数谱能量图的声源速度估计方案。实验和仿真数据验证了以上方法的有效性。 展开更多
关键词 相位线性化 warping变换 声源运动速度估计
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Cooperative Iteration Matching Method for Aligning Samples from Heterogeneous Industrial Datasets
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作者 LI Han SHI Guohong +1 位作者 LIU Zhao ZHU Ping 《Journal of Shanghai Jiaotong university(Science)》 2025年第2期375-384,共10页
Industrial data mining usually deals with data from different sources.These heterogeneous datasets describe the same object in different views.However,samples from some of the datasets may be lost.Then the remaining s... Industrial data mining usually deals with data from different sources.These heterogeneous datasets describe the same object in different views.However,samples from some of the datasets may be lost.Then the remaining samples do not correspond one-to-one correctly.Mismatched datasets caused by missing samples make the industrial data unavailable for further machine learning.In order to align the mismatched samples,this article presents a cooperative iteration matching method(CIMM)based on the modified dynamic time warping(DTW).The proposed method regards the sequentially accumulated industrial data as the time series.Mismatched samples are aligned by the DTW.In addition,dynamic constraints are applied to the warping distance of the DTW process to make the alignment more efficient.Then a series of models are trained with the cumulated samples iteratively.Several groups of numerical experiments on different missing patterns and missing locations are designed and analyzed to prove the effectiveness and the applicability of the proposed method. 展开更多
关键词 dynamic time warping mismatched samples sample alignment industrial data data missing
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C语言中堆区内存的追踪方法
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作者 王卫红 陈帅 《现代信息科技》 2025年第14期108-112,共5页
为追踪和监测C语言程序中堆区内存申请和释放的过程,并快速解决内存泄漏的问题,文章对堆区内存的使用和动态变化情况进行了研究,通过对内存管理、内存泄漏、内存追踪等问题的调研和实验,文章利用GNU连接器的WARP特性改写函数接口的方法... 为追踪和监测C语言程序中堆区内存申请和释放的过程,并快速解决内存泄漏的问题,文章对堆区内存的使用和动态变化情况进行了研究,通过对内存管理、内存泄漏、内存追踪等问题的调研和实验,文章利用GNU连接器的WARP特性改写函数接口的方法,改写了C语言标准库中malloc和free接口的实现,完成了可记录堆区内存使用的功能。通过红黑树数据结构来记录堆区内存的关键节点信息,提出了一种C语言中堆区内存的追踪方法,实现了改写malloc和free接口的软件方法。该方法在实现堆区内存追踪的同时,提高了增加、删除、查找节点的效率,能够有效降低堆区内存追踪和监测过程中对业务进程运行时间和效率的影响。 展开更多
关键词 C语言 内存追踪 内存泄漏 编译器WARP特性
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A short-term photovoltaic power prediction method based on improved spectral clustering-DTW and Stacking fusion
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作者 MEI Bingxiao MA Lyubin +2 位作者 YIN Jie XIE Zhiduo WANG Feng 《High Technology Letters》 2025年第3期288-299,共12页
Accurate short-term photovoltaic(PV)output forecasting is beneficial for increasing grid stabil-ity and enhancing the capacity for photovoltaic power absorption.In response to the challenges faced by commonly used pho... Accurate short-term photovoltaic(PV)output forecasting is beneficial for increasing grid stabil-ity and enhancing the capacity for photovoltaic power absorption.In response to the challenges faced by commonly used photovoltaic forecasting methods,which struggle to handle issues such as non-u-niform lengths of time series data for power generation and meteorological conditions,overlapping photovoltaic characteristics,and nonlinear correlations,an improved method that utilizes spectral clustering and dynamic time warping(DTW)for selecting similar days is proposed to optimize the dataset along the temporal dimension.Furthermore,XGBoost is employed for recursive feature selec-tion.On this basis,to address the issue that single forecasting models excel at capturing different data characteristics and tend to exhibit significant prediction errors under adverse meteorological con-ditions,an improved forecasting model based on Stacking and weighted fusion is proposed to reduce the independent bias and variance of individual models and enhance the predictive accuracy.Final-ly,experimental validation is carried out using real data from a photovoltaic power station in the Xi-aoshan District of Hangzhou,China,demonstrating that the proposed method can still achieve accu-rate and robust forecasting results even under conditions of significant meteorological fluctuations. 展开更多
关键词 photovoltaic output prediction feature dimension optimization recursive feature selection spectral clustering-dynamic time warping STACKING
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浅海双深度Warping变换融合无源测距
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作者 陈孟奇 郭良浩 +1 位作者 刘建军 张灵珊 《声学学报》 EI CAS CSCD 北大核心 2024年第2期263-273,共11页
针对浅海环境中利用单深度接收信号自相关函数的Warping变换方法测距时易出现的多值性问题,提出一种双深度Warping变换融合测距方法。该方法将双深度测量场的Warping变换提取结果与具有深度差异的拷贝场本征函数信息融合,判别简正波干... 针对浅海环境中利用单深度接收信号自相关函数的Warping变换方法测距时易出现的多值性问题,提出一种双深度Warping变换融合测距方法。该方法将双深度测量场的Warping变换提取结果与具有深度差异的拷贝场本征函数信息融合,判别简正波干涉项模态,提高测距的准确度。此外,针对实际海洋环境中测量场Warping变换特征峰位置难以准确提取的问题,将Warping变换的频率不变性与图像形态学方法结合以增强特征频率结构,提高后续测距的稳健性。海试数据处理结果显示,测距结果与实际距离符合较好,表明所提方法具有实际可行性。 展开更多
关键词 Warping变换 无源测距 垂直双阵元 浅海波导
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An Improved Machine Learning Model for Pure Component Property Estimation 被引量:2
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作者 Xinyu Cao Ming Gong +3 位作者 Anjan Tula Xi Chen Rafiqul Gani Venkat Venkatasubramanian 《Engineering》 SCIE EI CAS CSCD 2024年第8期61-73,共13页
Information on the physicochemical properties of chemical species is an important prerequisite when performing tasks such as process design and product design.However,the lack of extensive data and high experimental c... Information on the physicochemical properties of chemical species is an important prerequisite when performing tasks such as process design and product design.However,the lack of extensive data and high experimental costs hinder the development of prediction techniques for these properties.Moreover,accuracy and predictive capabilities still limit the scope and applicability of most property estimation methods.This paper proposes a new Gaussian process-based modeling framework that aims to manage a discrete and high-dimensional input space related to molecular structure representation with the group-contribution approach.A warping function is used to map discrete input into a continuous domain in order to adjust the correlation between different compounds.Prior selection techniques,including prior elicitation and prior predictive checking,are also applied during the building procedure to provide the model with more information from previous research findings.The framework is assessed using datasets of varying sizes for 20 pure component properties.For 18 out of the 20 pure component properties,the new models are found to give improved accuracy and predictive power in comparison with other published models,with and without machine learning. 展开更多
关键词 Group contribution Gaussian process Warping function Prior predictive checking
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An intelligent automatic correlation method of oilbearing strata based on pattern constraints:An example of accretionary stratigraphy of Shishen 100 block in Shinan Oilfield of Bohai Bay Basin,East China 被引量:1
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作者 WU Degang WU Shenghe +1 位作者 LIU Lei SUN Yide 《Petroleum Exploration and Development》 SCIE 2024年第1期180-192,共13页
Aiming at the problem that the data-driven automatic correlation methods which are difficult to adapt to the automatic correlation of oil-bearing strata with large changes in lateral sedimentary facies and strata thic... Aiming at the problem that the data-driven automatic correlation methods which are difficult to adapt to the automatic correlation of oil-bearing strata with large changes in lateral sedimentary facies and strata thickness,an intelligent automatic correlation method of oil-bearing strata based on pattern constraints is formed.We propose to introduce knowledge-driven in automatic correlation of oil-bearing strata,constraining the correlation process by stratigraphic sedimentary patterns and improving the similarity measuring machine and conditional constraint dynamic time warping algorithm to automate the correlation of marker layers and the interfaces of each stratum.The application in Shishen 100 block in the Shinan Oilfield of the Bohai Bay Basin shows that the coincidence rate of the marker layers identified by this method is over 95.00%,and the average coincidence rate of identified oil-bearing strata reaches 90.02% compared to artificial correlation results,which is about 17 percentage points higher than that of the existing automatic correlation methods.The accuracy of the automatic correlation of oil-bearing strata has been effectively improved. 展开更多
关键词 oil-bearing strata automatic correlation contrastive learning stratigraphic sedimentary pattern marker layer similarity measuring machine conditional constraint dynamic time warping algorithm
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Improving Badminton Action Recognition Using Spatio-Temporal Analysis and a Weighted Ensemble Learning Model
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作者 Farida Asriani Azhari Azhari Wahyono Wahyono 《Computers, Materials & Continua》 SCIE EI 2024年第11期3079-3096,共18页
Incredible progress has been made in human action recognition(HAR),significantly impacting computer vision applications in sports analytics.However,identifying dynamic and complex movements in sports like badminton re... Incredible progress has been made in human action recognition(HAR),significantly impacting computer vision applications in sports analytics.However,identifying dynamic and complex movements in sports like badminton remains challenging due to the need for precise recognition accuracy and better management of complex motion patterns.Deep learning techniques like convolutional neural networks(CNNs),long short-term memory(LSTM),and graph convolutional networks(GCNs)improve recognition in large datasets,while the traditional machine learning methods like SVM(support vector machines),RF(random forest),and LR(logistic regression),combined with handcrafted features and ensemble approaches,perform well but struggle with the complexity of fast-paced sports like badminton.We proposed an ensemble learning model combining support vector machines(SVM),logistic regression(LR),random forest(RF),and adaptive boosting(AdaBoost)for badminton action recognition.The data in this study consist of video recordings of badminton stroke techniques,which have been extracted into spatiotemporal data.The three-dimensional distance between each skeleton point and the right hip represents the spatial features.The temporal features are the results of Fast Dynamic Time Warping(FDTW)calculations applied to 15 frames of each video sequence.The weighted ensemble model employs soft voting classifiers from SVM,LR,RF,and AdaBoost to enhance the accuracy of badminton action recognition.The E2 ensemble model,which combines SVM,LR,and AdaBoost,achieves the highest accuracy of 95.38%. 展开更多
关键词 Weighted ensemble learning badminton action soft voting classifier joint skeleton fast dynamic time warping SPATIOTEMPORAL
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Time-Lapse Full-Waveform Inversion Using Cross-Correlation-Based Dynamic Time Warping
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作者 Jianhua Wang Qingping Li +1 位作者 Shouwei Zhou Yufa He 《哈尔滨工程大学学报(英文版)》 CSCD 2024年第3期634-644,共11页
Offshore carbon capture, utilization, and storage(OCCUS) is regarded as a crucial technology for mitigating greenhouse gas emissions.Quantitative monitoring maps of sealed carbon dioxide are necessary in a comprehensi... Offshore carbon capture, utilization, and storage(OCCUS) is regarded as a crucial technology for mitigating greenhouse gas emissions.Quantitative monitoring maps of sealed carbon dioxide are necessary in a comprehensive OCCUS project. A potential high-resolution method for the aforementioned purpose lies in the full-waveform inversion(FWI) of time-lapse seismic data. However, practical applications of FWI are severely restricted by the well-known cycle-skipping problem. A new time-lapse FWI method using cross-correlation-based dynamic time warping(CDTW) is proposed to detect changes in the subsurface property due to carbon dioxide(CO_(2)) injection and address the aforementioned issue. The proposed method, namely CDTW, which combines the advantages of cross-correlation and dynamic time warping, is employed in the automatic estimation of the discrepancy between the seismic signals simulated using the baseline/initial model and those acquired. The proposed FWI method can then back-project the estimated discrepancy to the subsurface space domain, thereby facilitating retrieval of the induced subsurface property change by taking the difference between the inverted baseline and monitor models. Numerical results on pairs of signals prove that CDTW can obtain reliable shifts under amplitude modulation and noise contamination conditions. The performance of CDTW substantially outperforms that of the conventional dynamic time warping method. The proposed time-lapse fullwaveform inversion(FWI) method is applied to the Frio-2 CO_(2) storage model. The baseline and monitor models are inverted from the corresponding time-lapse seismic data. The changes in velocity due to CO_(2) injection are reconstructed by the difference between the baseline and the monitor models. 展开更多
关键词 Full-waveform inversion Dynamic time warping Ocean carbon dioxide storage monitoring Discrepancy estimation Model test
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A convergent flow in warped product spaces
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作者 XIA Shu-can 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2024年第4期628-641,共14页
In this paper,we study a kind of curvature flow in warped product spaces.We obtain convergence results under barrier conditions and restrictions on prescribed function.We also obtain the asymptotic behavior of a kind ... In this paper,we study a kind of curvature flow in warped product spaces.We obtain convergence results under barrier conditions and restrictions on prescribed function.We also obtain the asymptotic behavior of a kind of inverse curvature flow in Schwarzschild manifold. 展开更多
关键词 curvature flow Minkowski problem warped product space
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Multiverse/Hyperverse Models: (4 + 1)-Dimensional Landscape (Black Saturns, Bousso-Hawking Nucleation, Gogberashvili Multiverses, Schwarzschild-De Sitter Nurseries) and a (3 + 1)-Dimensional Model for Dark Energy
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作者 Igor Yu. Potemine Werner Krause 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第4期1866-1877,共12页
We consider the Hyperverse as a collection of multiverses in a (4 + 1)-dimensional spacetime with gravitational constant G. Multiverses in our model are bouquets of thin shells (with synchronized intrinsic times). If ... We consider the Hyperverse as a collection of multiverses in a (4 + 1)-dimensional spacetime with gravitational constant G. Multiverses in our model are bouquets of thin shells (with synchronized intrinsic times). If gis the gravitational constant of a shell Sand εits thickness, then G~εg. The physical universe is supposed to be one of those thin shells inside the local bouquet called Local Multiverse. Other remarkable objects of the Hyperverse are supposed to be black holes, black lenses, black rings and (generalized) Black Saturns. In addition, Schwarzschild-de Sitter multiversal nurseries can be hidden inside those Black Saturns, leading to their Bousso-Hawking nucleation. It also suggests that black holes in our physical universe might harbor embedded (2 + 1)-dimensional multiverses. This is compatible with outstanding ideas and results of Bekenstein, Hawking-Vaz and Corda about “black holes as atoms” and the condensation of matter on “apparent horizons”. It allows us to formulate conjecture 12.1 about the origin of the Local Multiverse. As an alternative model, we examine spacetime warping of our universe by external universes. It gives data for the accelerated expansion and the cosmological constant Λ, which are in agreement with observation, thus opening a possibility for verification of the multiverse model. 展开更多
关键词 5-Dimensional Gravity Black Hole Black Saturn Cosmological Constant Dark Energy MULTIVERSE Spacetime Warping Thin Shell
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Isometric Immersions of Lightlike Warped Product Manifolds
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作者 Domitien Ndayirukiye Cyriaque Atindogbe Gilbert Nibaruta 《Journal of Applied Mathematics and Physics》 2024年第7期2490-2505,共16页
In this paper, we deal with isommetric immersions of globally null warped product manifolds into Lorentzian manifolds with constant curvature c in codimension k≥3. Under the assumptions that the globally null warped ... In this paper, we deal with isommetric immersions of globally null warped product manifolds into Lorentzian manifolds with constant curvature c in codimension k≥3. Under the assumptions that the globally null warped product manifold has no points with the same constant sectional curvature c as the Lorentzian ambient, we show that such isometric immersion splits into warped product of isometric immersions. 展开更多
关键词 Lightlike Warped Product Manifolds Globally Null Warped Products Manifolds Lightlike Warped Product Isometric Immersions
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Crealet presents its innovative warp tension solutions at Techtextil 2024
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《China Textile》 2024年第2期43-43,共1页
Crealet is the world leader in sophisticated warp feeding technology and tailored solutions.Controlled warp tension stands also for controlled fabric quality.The Swiss firm presents its latest developments for technic... Crealet is the world leader in sophisticated warp feeding technology and tailored solutions.Controlled warp tension stands also for controlled fabric quality.The Swiss firm presents its latest developments for technical textile applications at Techtextil 2024 in Frankfurt,Germany. 展开更多
关键词 tension WARP GERMANY
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MRI去金属伪影WARP序列在关节假体周围感染中的应用
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作者 于亚颖 张娟 《中文科技期刊数据库(文摘版)医药卫生》 2024年第5期005-008,共4页
MRI去金属伪影WARP序列在关节假体周围感染中的应用。方法 选取2021年1月-2022年12月本院收治的关节假体周围感染患者62例为观察对象,62例患者均接受常规序列、WARP序列检查。分析62例患者的诊断效果。结果 WARP序列检查最大层面伪影平... MRI去金属伪影WARP序列在关节假体周围感染中的应用。方法 选取2021年1月-2022年12月本院收治的关节假体周围感染患者62例为观察对象,62例患者均接受常规序列、WARP序列检查。分析62例患者的诊断效果。结果 WARP序列检查最大层面伪影平均面积优于常规序列(P〈0.05);WARP序列检查 图像清晰度、手术指导作用、信噪比优于常规序列(P〈0.05)。结论 MRI去金属伪影WARP序列可以在关节假体周围感染的诊断、评估中起到积极作用。 展开更多
关键词 关节假体周围感染 MRI 常规序列 WARP序列
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The Effects of the Longitudinal Axis of Loading upon Bending, Shear and Torsion of a Thin-Walled Cantilever Channel Beam
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作者 David W. A. Rees Abdelraouf M. Sami Alsheikh 《World Journal of Mechanics》 2024年第5期73-96,共24页
Three aluminium channel sections of US standard extruded dimension are mounted as cantilevers with x-axis symmetry. The flexural bending and shear that arise with applied axial torsion are each considered theoreticall... Three aluminium channel sections of US standard extruded dimension are mounted as cantilevers with x-axis symmetry. The flexural bending and shear that arise with applied axial torsion are each considered theoretically and numerically in terms of two longitudinal axes of loading not coincident with the shear centre. In particular, the warping displacements, stiffness and stress distributions are calculated for torsion applied to longitudinal axes passing through the section’s centroid and its web centre. The stress conversions derived from each action are superimposed to reveal a net sectional stress distribution. Therein, the influence of the axis position upon the net axial and shear stress distributions is established compared to previous results for each beam when loading is referred to a flexural axis through the shear centre. Within the net stress analysis is, it is shown how the constraint to free warping presented by the end fixing modifies the axial stress. The latter can be identified with the action of a ‘bimoment’ upon each thin-walled section. 展开更多
关键词 Thin-Aluminium Channels Cantilever Beam Bending Shear Torsion WARPING BIMOMENT Flexural Axis Centre of Twist CENTROID Shear Centre Torsional Stiffness Constrained Stress
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Theory of Flexural Shear, Bending and Torsion for a Thin-Walled Beam of Open Section
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作者 David W. A. Rees Abdelraouf M. Sami Alsheikh 《World Journal of Mechanics》 2024年第3期23-53,共31页
Aspects of the general Vlasov theory are examined separately as applied to a thin-walled channel section cantilever beam under free-end end loading. In particular, the flexural bending and shear that arise under trans... Aspects of the general Vlasov theory are examined separately as applied to a thin-walled channel section cantilever beam under free-end end loading. In particular, the flexural bending and shear that arise under transverse shear and axial torsional loading are each considered theoretically. These analyses involve the location of the shear centre at which transverse shear forces when applied do not produce torsion. This centre, when taken to be coincident with the centre of twist implies an equivalent reciprocal behaviour. That is, an axial torsion applied concentric with the shear centre will twist but not bend the beam. The respective bending and shear stress conversions are derived for each action applied to three aluminium alloy extruded channel sections mounted as cantilevers with a horizontal principal axis of symmetry. Bending and shear are considered more generally for other thin-walled sections when the transverse loading axes at the shear centre are not parallel to the section = s centroidal axes of principal second moments of area. The fixing at one end of the cantilever modifies the St Venant free angular twist and the free warping displacement. It is shown from the Wagner-Kappus torsion theory how the end constrained warping generates an axial stress distribution that varies with the length and across the cross-section for an axial torsion applied to the shear centre. It should be mentioned here for wider applications and validation of the Vlasov theory that attendant papers are to consider in detail bending and torsional loadings applied to other axes through each of the centroid and the web centre. Therein, both bending and twisting arise from transverse shear and axial torsion applied to each position being displaced from the shear centre. Here, the influence of the axis position upon the net axial and shear stress distributions is to be established. That is, the net axial stress from axial torsional loading is identified with the sum of axial stress due to bending and axial stress arising from constrained warping displacements at the fixing. The net shear stress distribution overlays the distributions from axial torsion and that from flexural shear under transverse loading. Both arise when transverse forces are displaced from the shear centre. 展开更多
关键词 Thin Wall Theory Cantilever Beam Open Channel Section Principal Axes Flexure Transverse Shear TORSION Shear Centre Shear Flow WARPING Fixed-End Constraint
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一种基于warping变换的浅海脉冲声源被动测距方法 被引量:15
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作者 王冬 郭良浩 +1 位作者 刘建军 戚聿波 《物理学报》 SCIE EI CAS CSCD 北大核心 2016年第10期138-146,共9页
针对浅海波导中脉冲声源被动测距问题,提出了一种利用接收信号的能量密度函数进行warping变换的声源被动测距方法.对于浅海波导,接收信号的能量密度函数中不同号简正波相干部分,经warping变换后输出结果的频谱中包含与声源和接收器位置... 针对浅海波导中脉冲声源被动测距问题,提出了一种利用接收信号的能量密度函数进行warping变换的声源被动测距方法.对于浅海波导,接收信号的能量密度函数中不同号简正波相干部分,经warping变换后输出结果的频谱中包含与声源和接收器位置无关的不变性频率特征.这些特征频率在数值上等于理想波导中相干的两号简正波的截止频率差,与海底参数无关,因此仅需已知海水中的平均声速和海水深度便可计算出特征频率值.当声源距离未知时,利用特征频率的提取值与真实特征频率之间的关系可以实现快速测距,极大地提高了计算速度.为了验证方法的有效性,对2011年11月黄海海域水声实验的接收脉冲数据进行了处理,测距结果与实测距离符合良好,平均测距误差在8%以内. 展开更多
关键词 浅海 被动测距 warping变换 能量密度函数
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一种基于双引导声源和warping变换的拷贝声场计算方法 被引量:6
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作者 姚美娟 鹿力成 +1 位作者 马力 郭圣明 《声学学报》 EI CSCD 北大核心 2016年第1期73-80,共8页
提出了在均匀浅海环境中只知道少量环境参数的情况下,利用不同距离上的两枚引导声源和warping变换的拷贝声场计算方法。这种方法主要基于简正波估计技术,从声场衰减信息和相位信息两个方向来重构拷贝声场,从而与目标声场匹配进行定... 提出了在均匀浅海环境中只知道少量环境参数的情况下,利用不同距离上的两枚引导声源和warping变换的拷贝声场计算方法。这种方法主要基于简正波估计技术,从声场衰减信息和相位信息两个方向来重构拷贝声场,从而与目标声场匹配进行定位。其优点在于能避免传统的匹配场定位技术中拷贝场计算时对环境模型和环境参数的依赖。在简正波估计技术中采用warping变换的处理方式,数值仿真主要采用线性Bartlett匹配处理器分析了目标定位效果,在信噪比高于10-15dB的情况下,定位效果良好。 展开更多
关键词 WARPING 声场计算 双引导 拷贝 声源 定位技术 环境参数 相位信息
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