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Three-dimensional Holographic Vector of Atomic Interaction Field(3D-HoVAIF) for the QSPR/QSAR of Polychlorinated Naphthalenes 被引量:1
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作者 李正华 陈刚 +3 位作者 陈志涛 夏之宁 程凡圣 陈华 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2012年第3期345-352,共8页
Three-dimensional holographic vector of atomic interaction field(3D-HoVAIF) is used to describe the chemical structures of polychlorinated naphthalenes(PCNs).After variable screening by stepwise multiple regressio... Three-dimensional holographic vector of atomic interaction field(3D-HoVAIF) is used to describe the chemical structures of polychlorinated naphthalenes(PCNs).After variable screening by stepwise multiple regression(SMR) technique,the liner relationships between gas-chromatographic relative retention time(RRT),298 K supercooled liquid pressures(logPL),n-octanol/air partition coefficient(logKOA),n-octanol/water partition coefficient(logKOW),aqueous solubilities(logSW),relative in vitro potency values(-logEROD) of PCNs and 3D-HoVAIF descriptors have been established by partial least-square(PLS) regression.The result shows that the 3D-HoVAIF descriptors can be well used to express the quantitative structure-property(activity) relationships of PCNs.Predictive capability of the models has also been demonstrated by leave-one-out cross-validation.Moreover,the predicted values have been presented for those PCNs which are lack of experimentally physico-chemical properties and biological activity by the optimum models. 展开更多
关键词 polychlorinated naphthalenes three-dimensional holographic vector of atomic interaction field QSPR QSAR
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On the Rotation of a Vector Field in a Four-Dimensional Space
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作者 Leonardo Simal Moreira 《Applied Mathematics》 2014年第1期128-136,共9页
Recently I published a paper in the journal ALAMT (Advances in Linear Algebra & Matrix Theory) and explored the possibility of obtaining products of vectors in dimensions higher than three [1]. In continuation to ... Recently I published a paper in the journal ALAMT (Advances in Linear Algebra & Matrix Theory) and explored the possibility of obtaining products of vectors in dimensions higher than three [1]. In continuation to this work, it is proposed to develop, through dimensional analogy, a vector field with notation and properties analogous to the curl, in this case applied to the space IR4. One can see how the similarities are obvious in relation to the algebraic properties and the geometric structures, if the rotations are compared in spaces of three and four dimensions. 展开更多
关键词 Products of vectorS dimensional ANALOGY vector FIELDS CURL ROTATIONS CURL by ANALOGY
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On a Hypothetical Vector Field Associated with the Classic Electromagnetic Wave in a Space of Four Dimensions
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作者 Leonardo Simal Moreira 《Journal of Applied Mathematics and Physics》 2020年第12期2836-2845,共10页
In two previous papers <a href="#ref1">[1]</a> and <a href="#ref2">[2]</a>, a structure for vector products in <em>n</em> dimensions was presented, and at the sa... In two previous papers <a href="#ref1">[1]</a> and <a href="#ref2">[2]</a>, a structure for vector products in <em>n</em> dimensions was presented, and at the same time it was possible to propose the existence of a vector analogous to the curl of a vector field, for a space of four dimensions. In continuation of these works, the objective is to develop, through dimensional analogy, the idea of a hypothetical vector field, associated with the classical electromagnetic wave. This hypothetical field has a possible mathematical existence only when considering a space of four dimensions. The properties of the electromagnetic wave are preserved and equations with mathematical forms analogous to those of Maxwell’s equations are presented. 展开更多
关键词 dimensional Analogy Electromagnetic Wave Four-dimensional Space vector Fields in Four dimensions Analog of Maxwell’s Equations
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Completeness of system of root vectors of upper triangular infinitedimensional Hamiltonian operators appearing in elasticity theory 被引量:1
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作者 王华 阿拉坦仓 黄俊杰 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2012年第3期385-398,共14页
This paper deals with a class of upper triangular infinite-dimensional Hamilto- nian operators appearing in the elasticity theory. The geometric multiplicity and algebraic index of the eigenvalue are investigated. Fur... This paper deals with a class of upper triangular infinite-dimensional Hamilto- nian operators appearing in the elasticity theory. The geometric multiplicity and algebraic index of the eigenvalue are investigated. Furthermore, the algebraic multiplicity of the eigenvalue is obtained. Based on these properties, the concrete completeness formulation of the system of eigenvectors or root vectors of the Hamiltonian operator is proposed. It is shown that the completeness is determined by the system of eigenvectors of the operator entries. Finally, the applications of the results to some problems in the elasticity theory are presented. 展开更多
关键词 upper triangular infinite-dimensional Hamiltonian operator EIGENvector root vector MULTIPLICITY COMPLETENESS
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基于跨粒度HFLTS语义向量距离的军事评估方法
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作者 杜秀丽 周睿 +3 位作者 程伟龙 吕亚娜 邱少明 文世喜 《火力与指挥控制》 北大核心 2026年第2期38-46,共9页
犹豫模糊语言术语集可以更好地反映专家在军事评估中的意见,但不同专家的偏好排序相同、数值差度大时,现有距离测度难以准确反映专家的实际意见。针对上述问题,引入考虑投影值的因素,定义了由犹豫度和语义值构成的二元向量,提出跨粒度... 犹豫模糊语言术语集可以更好地反映专家在军事评估中的意见,但不同专家的偏好排序相同、数值差度大时,现有距离测度难以准确反映专家的实际意见。针对上述问题,引入考虑投影值的因素,定义了由犹豫度和语义值构成的二元向量,提出跨粒度犹豫模糊语言术语集的语义向量距离,将该距离用于基于跨粒度犹豫模糊语言术语集语义向量距离的军事评估,并通过军事评估大群体决策相关案例验证可行性。 展开更多
关键词 军事评估 投影值 二元向量 跨粒度 语义向量距离
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Automated measurement of three-dimensional cerebral cortical thickness in Alzheimer’s patients using localized gradient vector trajectory in fuzzy membership maps
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作者 Chiaki Tokunaga Hidetaka Arimura +9 位作者 Takashi Yoshiura Tomoyuki Ohara Yasuo Yamashita Kouji Kobayashi Taiki Magome Yasuhiko Nakamura Hiroshi Honda Hideki Hirata Masafumi Ohki Fukai Toyofuku 《Journal of Biomedical Science and Engineering》 2013年第3期327-336,共10页
Our purpose in this study was to develop an automated method for measuring three-dimensional (3D) cerebral cortical thicknesses in patients with Alzheimer’s disease (AD) using magnetic resonance (MR) images. Our prop... Our purpose in this study was to develop an automated method for measuring three-dimensional (3D) cerebral cortical thicknesses in patients with Alzheimer’s disease (AD) using magnetic resonance (MR) images. Our proposed method consists of mainly three steps. First, a brain parenchymal region was segmented based on brain model matching. Second, a 3D fuzzy membership map for a cerebral cortical region was created by applying a fuzzy c-means (FCM) clustering algorithm to T1-weighted MR images. Third, cerebral cortical thickness was three- dimensionally measured on each cortical surface voxel by using a localized gradient vector trajectory in a fuzzy membership map. Spherical models with 3 mm artificial cortical regions, which were produced using three noise levels of 2%, 5%, and 10%, were employed to evaluate the proposed method. We also applied the proposed method to T1-weighted images obtained from 20 cases, i.e., 10 clinically diagnosed AD cases and 10 clinically normal (CN) subjects. The thicknesses of the 3 mm artificial cortical regions for spherical models with noise levels of 2%, 5%, and 10% were measured by the proposed method as 2.953 ± 0.342, 2.953 ± 0.342 and 2.952 ± 0.343 mm, respectively. Thus the mean thicknesses for the entire cerebral lobar region were 3.1 ± 0.4 mm for AD patients and 3.3 ± 0.4 mm for CN subjects, respectively (p < 0.05). The proposed method could be feasible for measuring the 3D cerebral cortical thickness on individual cortical surface voxels as an atrophy feature in AD. 展开更多
关键词 Alzheimer’s Disease (AD) Fuzzy C-MEANS Clustering (FCM) THREE-dimensionAL CEREBRAL CORTICAL Thickness LOCALIZED Gradient vector
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基于三维向量模型的城市高强度片区界定与测度方法研究
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作者 李晓宇 梅玥 +1 位作者 李舒扬 玄峰 《华中建筑》 2026年第1期131-135,共5页
城市高强度片区作为当前实现城市空间治理的关键中观单元,其概念界定与测度方法是落实城市设计管控与体检更新的重要前提。研究在扎根相关法定规划文件与学术文献的基础上,凝练出以“建设、交通、功能”三维度空间特征为核心的内涵框架... 城市高强度片区作为当前实现城市空间治理的关键中观单元,其概念界定与测度方法是落实城市设计管控与体检更新的重要前提。研究在扎根相关法定规划文件与学术文献的基础上,凝练出以“建设、交通、功能”三维度空间特征为核心的内涵框架,并据此构建三维向量测度模型,提出针对城市高强度片区界定指标及测度方法,并通过搭建国内典型城市高强度片区案例库,初步测度国内现阶段高强度片区界定参考值及指标分布特征,在城市设计中观尺度上为高强度片区的空间问题诊断与设计导控提供量化描述参照。 展开更多
关键词 高强度片区 概念界定 测度方法 三维向量模型
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分布式光纤网络中均一性序列数据异常值挖掘方法
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作者 胡秋生 胡璋 +1 位作者 刘志鹏 曾文辉 《激光杂志》 北大核心 2026年第1期113-118,共6页
光纤网络中的均一性序列数据具有高维度的特点,数据在高维空间中的稀疏性较强,导致正常点和异常点之间的距离差异变得不明显,增加了准确挖掘异常值的难度。故提出针对分布式光纤网络中均一性序列数据的异常值挖掘方法。使用PCA降维方法... 光纤网络中的均一性序列数据具有高维度的特点,数据在高维空间中的稀疏性较强,导致正常点和异常点之间的距离差异变得不明显,增加了准确挖掘异常值的难度。故提出针对分布式光纤网络中均一性序列数据的异常值挖掘方法。使用PCA降维方法对均一性序列数据展开降维处理,采用LDA降维方法对降维后的数据再次展开降维处理,通过降低数据稀疏性,更准确地区分正常和异常数据的投影方向,使二者在低维空间中能够被更明显地区分,通过编码与解码的方式提取降维后的数据特征,将数据特征输入支持向量机内,输出均一性序列数据异常值挖掘结果。实验结果表明,该方法的误报率和漏报率均为0,F1评分分值一直保持在3分以上,提升了异常值的挖掘精度与准确性。 展开更多
关键词 分布式光纤 均一性序列数据 PCA与LDA的数据降维方法 稀疏自编码器 支持向量机
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基于近红外光谱的羊绒羊毛鉴别降维方法比较
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作者 陈鑫 王芳 +1 位作者 陈锦妮 王如 《西安工程大学学报》 2026年第1期1-9,共9页
不同品种的羊绒羊毛在纤维特性、保暖性、柔软度和外观等方面存在差异,这些差异直接影响产品的质量和市场价值。因此,快速、准确地鉴别羊绒羊毛品种对于提升产品品质和增强市场竞争力具有重要意义。为克服传统检测方法在效率与成本上的... 不同品种的羊绒羊毛在纤维特性、保暖性、柔软度和外观等方面存在差异,这些差异直接影响产品的质量和市场价值。因此,快速、准确地鉴别羊绒羊毛品种对于提升产品品质和增强市场竞争力具有重要意义。为克服传统检测方法在效率与成本上的局限,以及近红外光谱数据所具有的高维性、非线性及光谱重叠等挑战,提出一种基于近红外光谱技术的羊绒羊毛品种快速无损鉴别方法。实验样本涵盖14个品种、420个羊绒羊毛样品。首先通过线性判别分析(linear discriminant analysis,LDA)对高维光谱数据进行降维处理,随后结合灰狼优化算法(grey wolf optimizer,GWO)优化支持向量机(support vector machine,SVM)模型的参数,构建了LDA-GWO-SVM联合判别模型。同时,对线性方法的主成分分析(principal component analysis,PCA)及非线性方法的局部线性嵌入(locally linear embedding,LLE)和等距特征映射(isometric feature mapping,ISOMAP)等多种降维算法的性能进行比较。结果表明,线性方法在降维方面表现优异,且LDAGWO-SVM模型在11个主因子数下的分类准确率达到99.21%。将近红外光谱技术与机器学习相结合,为羊绒羊毛品种鉴别提供了一种新的方法,在实际应用中为实现快速、准确的品种识别和质量控制提供了有效支持。 展开更多
关键词 羊绒 羊毛 近红外光谱 维度降低 品种鉴别 支持向量机
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基于近红外光谱鉴别麻纤维
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作者 朱玥莹 王守波 郁崇文 《上海纺织科技》 2026年第1期59-63,共5页
为了建立一种能够快速、准确鉴别麻纤维种类的方法,收集了不同产地、批次,且脱胶程度不同的大麻、亚麻、苎麻、黄麻和罗布麻纤维,共180种。基于不同麻纤维近红外光谱的特征,利用偏最小二乘法、支持向量机与一维卷积神经网络3种模型,分... 为了建立一种能够快速、准确鉴别麻纤维种类的方法,收集了不同产地、批次,且脱胶程度不同的大麻、亚麻、苎麻、黄麻和罗布麻纤维,共180种。基于不同麻纤维近红外光谱的特征,利用偏最小二乘法、支持向量机与一维卷积神经网络3种模型,分别对纤维样品进行鉴别,并比较了各建模方法的准确度。结果表明:一维卷积神经网络建模准确性最高,5种麻纤维的鉴别准确率均能达到100%;支持向量机建模效果次之,5种麻纤维的鉴别准确率均大于92%;偏最小二乘法模型的准确性较差,对5种麻纤维的鉴别准确率均低于90%。试验结果可为近红外光谱技术鉴别麻纤维提供参考。 展开更多
关键词 麻纤维 鉴别 近红外光谱 一维卷积神经网络 支持向量机 偏最小二乘法
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基于升维处理的直升机传动系统特征提取及故障诊断方法
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作者 李峰 《科学技术创新》 2026年第4期17-20,共4页
本文提出了一种基于升维处理的传动系统特征提取与故障诊断方法。采用转速同步信号的升维处理方法,将一维振动信号转换成二维振动信号。在此基础上,联合应用LBM算法与GLCM算法,从二维振动信号中提取特征信息,输入到SVM故障诊断模型中,... 本文提出了一种基于升维处理的传动系统特征提取与故障诊断方法。采用转速同步信号的升维处理方法,将一维振动信号转换成二维振动信号。在此基础上,联合应用LBM算法与GLCM算法,从二维振动信号中提取特征信息,输入到SVM故障诊断模型中,得出故障诊断结果。从实际应用效果来看,基于升维处理的传动系统特征提取与故障诊断模型,对传动系统故障的诊断准确率在99.5%以上,对降低故障维修费用和保障直升机飞行安全有积极帮助。 展开更多
关键词 直升机传动系统 特征提取 升维处理 支持向量机 故障诊断
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Three-Dimensional Analysis of Rolling by Twin Shear Stress Yield Criterion 被引量:4
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作者 ZHAO De-wen XIE Ying-jie LIU Xiang-hua WANG Guo-dong 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2006年第6期21-26,共6页
Using the twin shear stress yield criterion, the surface integral of the co-line vectors, and the integration depending on upper limit, Kobayashi's three-dimensional velocity field of rolling was analyzed and an anal... Using the twin shear stress yield criterion, the surface integral of the co-line vectors, and the integration depending on upper limit, Kobayashi's three-dimensional velocity field of rolling was analyzed and an analytical expression of rolling torque and single force was obtained. Through redoing the same experiment of rolling pure lead as Sims, the calculated results by the above expression were compared with those of Kobayashi and Sims formulae. The results show that the twin shear stress yield criterion is available for rolling analysis and the calculated results by the new formula are a little higher than those by Kobayashi and Sims ones if the reduction ratio is less than 30%. 展开更多
关键词 twin shear stress yield criterion co-line vector integral three-dimensional rolling analytical solution
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Hybrid calibration method for six-component force/torque transducers of wind tunnel balance based on support vector machines 被引量:4
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作者 Ma Yingkun Xie Shilin +1 位作者 Zhang Xinong Luo Yajun 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2013年第3期554-562,共9页
A hybrid calibration approach based on support vector machines (SVM) is proposed to characterize nonlinear cross coupling of multi-dimensional transducer. It is difficult to identify these unknown nonlinearities and... A hybrid calibration approach based on support vector machines (SVM) is proposed to characterize nonlinear cross coupling of multi-dimensional transducer. It is difficult to identify these unknown nonlinearities and crosstalk just with a single conventional calibration approach. In this paper, a hybrid model comprising calibration matrix and SVM model for calibrating linearity and nonlinearity respectively is built up. The calibration matrix is determined by linear artificial neural network (ANN), and the SVM is used to compensate for the nonlinear cross coupling among each dimension. A simulation of the calibration of a multi-dimensional sensor is conducted by the SVM hybrid calibration method, which is then utilized to calibrate a six-component force/torque transducer of wind tunnel balance. From the calibrating results, it can be indicated that the SVM hybrid calibration method has improved the calibration accuracy significantly without increasing data samples, compared with calibration matrix. Moreover, with the calibration matrix, the hybrid model can provide a basis for the design of transducers. 展开更多
关键词 HYBRID MULTI-dimensionAL Nonlinear coupling Support vector machines Transducers
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On the ascent of infinite dimensional Hamiltonian operators
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作者 吴德玉 陈阿拉坦仓 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第8期421-425,共5页
In this paper, the ascent of 2 × 2 infinite dimensional Hamiltonian operators and a class of 4 × 4 infinite dimensional Hamiltonian operators are studied, and the conditions under which the ascent of 2 ×... In this paper, the ascent of 2 × 2 infinite dimensional Hamiltonian operators and a class of 4 × 4 infinite dimensional Hamiltonian operators are studied, and the conditions under which the ascent of 2 × 2 infinite dimensional Hamiltonian operator is 1 and the ascent of a class of 4 × 4 infinite dimensional Hamiltonian operators that arises in study of elasticity is2 are obtained. Concrete examples are given to illustrate the effectiveness of criterions. 展开更多
关键词 root vector COMPLETENESS infinite dimensional Hamiltonian operator ASCENT
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A New Algorithm for Reducing Dimensionality of L1-CSVM Use Augmented Lagrange Method
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作者 Mingzhu Cui Liya Fan 《Journal of Applied Mathematics and Physics》 2022年第1期21-30,共10页
Principal component analysis and generalized low rank approximation of matrices are two different dimensionality reduction methods. Two different dimensionality reduction algorithms are applied to the L1-CSVM model ba... Principal component analysis and generalized low rank approximation of matrices are two different dimensionality reduction methods. Two different dimensionality reduction algorithms are applied to the L1-CSVM model based on augmented Lagrange method to explore the variation of running time and accuracy of the model in dimensionality reduction space. The results show that the improved algorithm can greatly reduce the running time and improve the accuracy of the algorithm. 展开更多
关键词 Support vector Machine dimensionality Reduction Augmented Lagrange Method Classification
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Analytical Solution for Three-dimensional Forging Taking into Account Bulging of Sides by Mean Yield Criterion 被引量:1
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作者 DU Haijun ZHAO Dewen WANG Genji WANG Guodong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2010年第4期477-483,共7页
Currently, for some complex plastic deformations, the analytical solution can not be obtained by using Mises yield criterion, because Mises yield criterion is nine dimensions, the velocity field is complex, and the so... Currently, for some complex plastic deformations, the analytical solution can not be obtained by using Mises yield criterion, because Mises yield criterion is nine dimensions, the velocity field is complex, and the solving methods are not innovative. Corresponding solutions of these problems are that yield criterion is linearized to reduce the variable numbers, and the velocity field and the solving methods are reasonably simplified, respectively. In this paper, a new linear yield criterion--mean yield(MY) criterion and inner-product of strain rate vector are used to analytically solve 3D forging taking into account bugling of sides. The velocity field is expressed as a vector in three dimensions, and rotation and divergence are applied to confirm that the velocity field is kinematically admissible. Then, the corresponding strain rate tensor of the velocity field is transformed into principal one by making the determinant of coefficients of the tensor cubic equation be zero. By using MY criterion, the plastic power is term by term integrated and summed according to inner-product of strain rate vector. An upper bound analytical solution is obtained for the forging, and verified by a pure lead press test. The test result turns out that the total pressure calculated by MY criterion is higher by 2.5%-15% than measuring value. In addition, a measuring formula of bulging parameter (a) is proposed, but the values of a measured by the formula are lower than those optimized by the golden section search. The total pressure calculated by MY criterion is compared with the ones by twin shear, Trasca yield, and Mises yield criterion. The comparing result shows that the total pressure calculated by MY criterion is slightly higher than the mean value of that by twin shear and Trasca yield criterion, and lower than that by Mises yield criterion, but more close to that by Mises yield criterion compared with that by other two. The proposed analytical solving methods can be effectively used to other complex plastic deformation, simplifying the solving process and obtaining the reasonable results. 展开更多
关键词 mean yield criterion three-dimensional forging BULGING strain rate vector inner-product
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基于自定函数的支持向量机电池故障诊断方法
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作者 蔡君同 刘尧 +1 位作者 雷南林 郝雄博 《中国汽车(中英文对照)》 2026年第3期149-156,共8页
随着电动汽车的普及,电池故障的准确诊断成为保障车辆安全和性能的重要环节。本文提出了一种基于分段网格搜索优化和自定义评分函数的支持向量回归(SVR)方法,用于电动车电池故障诊断。首先,通过数据清洗和切片对多台电动车1个月的运行... 随着电动汽车的普及,电池故障的准确诊断成为保障车辆安全和性能的重要环节。本文提出了一种基于分段网格搜索优化和自定义评分函数的支持向量回归(SVR)方法,用于电动车电池故障诊断。首先,通过数据清洗和切片对多台电动车1个月的运行数据进行处理,并提取关键特征参数。然后,利用皮尔森相关系数进行数据降维,简化数据集。接着,通过Min-Max标准化方法进行数据预处理,并采用分段网格搜索优化SVR模型参数。最后,设计自定义评分函数,从多个维度评估模型的预测效果。实验结果表明,该方法在故障识别准确率和预测精度方面表现出色,能够有效识别电池故障及其严重程度,为电动车电池故障诊断提供了可靠的技术支持。 展开更多
关键词 电动车电池 故障诊断 支持向量回归(SVR) 分段网格搜索 自定义评分函数 数据降维
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Quantitative Structure Activity Relationship Studies of Benzoxazinone Derivative Antithrombotic Drug Using New Three-dimensional Structure Descriptors
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作者 仝建波 李云飞 +1 位作者 刘淑玲 孟元亮 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2010年第12期1893-1899,共7页
A novel three-dimensional holographic vector of atomic interaction field(3D-HoVAIF) was used to describe the chemical structures of 23 benzoxazinone derivatives as antithrombotic drugs.Here a quantitative structure ... A novel three-dimensional holographic vector of atomic interaction field(3D-HoVAIF) was used to describe the chemical structures of 23 benzoxazinone derivatives as antithrombotic drugs.Here a quantitative structure activity relationship(QSAR) model was built by partial least-squares(PLS) regression.The estimation stability and prediction ability of the model were strictly analyzed by both internal and external validations.The correlation coefficients of established PLS model,leave-one-out(LOO) cross-validation,and predicted values versus experimental ones of external samples were R2=0.899,RCV2=0.854 and Qext2=0.868,respectively.These values indicated that the built PLS model had both favorable estimation stability and good prediction capabilities.Furthermore,the satisfactory results showed that 3D-HoVAIF could preferably express the information related to the biological activity of benzoxazinone derivatives. 展开更多
关键词 benzoxazinone derivatives antithrombotic drug three-dimensional holographic vector of atomic interaction field(3D-HoVAIF) quantitative structure-activity relationship(QSAR)
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基于OCSVM的行业负荷特征异常辨识方法
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作者 陈光宇 杨光 +3 位作者 施蔚锦 蔡鑫灿 陈婉清 刘昊 《电力工程技术》 北大核心 2026年第2期70-79,共10页
为解决近年来用户行业变化特性加剧导致的难以准确辨识用户档案信息变动的问题,文中提出一种基于数据驱动的负荷特征异常辨识方法。首先,提出一种两阶段行业典型负荷形态构建方法,利用基于层次密度的含噪声应用空间聚类(hierarchical de... 为解决近年来用户行业变化特性加剧导致的难以准确辨识用户档案信息变动的问题,文中提出一种基于数据驱动的负荷特征异常辨识方法。首先,提出一种两阶段行业典型负荷形态构建方法,利用基于层次密度的含噪声应用空间聚类(hierarchical density-based spatial clustering of applications with noise,HDBSCAN)提取用户在不同场景下的典型日负荷曲线,并利用改进的K-means算法对提取出的典型日负荷曲线进行聚类分析,构建行业的典型负荷形态;其次,提出一种多维场景负荷特征异常智能研判方法,通过构造用户的负荷特征,使用熵权法评估行业典型场景的相对重要性,并采用单分类支持向量机(one-class support vector machine,OCSVM)算法量化每个场景下的用户负荷特征的异常程度,通过加权计算得到用户的综合嫌疑得分并排序,从而实现对负荷特征异常用户的准确辨识。最后,采用某地区实际用户数据进行算例验证。仿真结果表明,所提方法在行业典型负荷场景构建及负荷特征异常辨识方面表现出良好的可行性与实用价值。 展开更多
关键词 数据驱动 负荷特征异常 基于层次密度的含噪声应用空间聚类(HDBSCAN)-改进K-means算法 多维场景分析 单分类支持向量机(OCSVM) 综合嫌疑得分
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基于地震资料计算断层滑动矢量的四维搜索区域古应力计算方法
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作者 杨宇 吉礼东 +3 位作者 刘芳 颜平 徐春阳 吴昌荣 《石油地球物理勘探》 北大核心 2025年第2期431-439,共9页
区域古应力控制断层与裂缝的发育,因此准确了解区域古应力对油气勘探与开发具有重要意义。基于Wallace-Bott假设,采用断层滑动矢量结合四维搜索法可以较为准确地计算区域古应力。目前,一般使用地面露头的断层擦痕表示断层的滑动矢量,但... 区域古应力控制断层与裂缝的发育,因此准确了解区域古应力对油气勘探与开发具有重要意义。基于Wallace-Bott假设,采用断层滑动矢量结合四维搜索法可以较为准确地计算区域古应力。目前,一般使用地面露头的断层擦痕表示断层的滑动矢量,但是地面擦痕反映的地面应力状态与地下应力状态存在差异。因此,引入一种基于三维地震资料直接计算断层滑动矢量的方法。首先,构建垂直或水平地震剖面并读取视走向滑移与视倾斜滑移,并通过数学方法计算断层滑动矢量;然后,在此基础上采用四维搜索法计算区域古应力。以新场须二气藏M区块为例,计算了两条断层的18个断层滑动矢量,并将其随机分为5组,采用四维搜索法分别计算每一组的区域古应力,并评价区域古应力张量在断面上的剪切应力方向与实际断层滑移方向的偏差(RUP值)。结果显示,5组方案平均RUP值均小于50%,表明该方法计算区域古应力的结果准确,可以推广应用于类似地区。 展开更多
关键词 地震资料 断层滑动矢量 古应力反演 四维搜索法
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