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Position Group Contribution Method for Predicting the Normal Boiling Point of Organic Compounds 被引量:7
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作者 王强 马沛生 +1 位作者 王昶 夏淑倩 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第2期254-258,共5页
A new position group contribution model is proposed for the estimation of normal boiling data of organic compounds involving a carbon chain from C2 to C18.The characteristic of this method is the use of position distr... A new position group contribution model is proposed for the estimation of normal boiling data of organic compounds involving a carbon chain from C2 to C18.The characteristic of this method is the use of position distribution function.It could distinguish most of isomers that include cis-or trans-structure from organic compounds.Contributions for hydrocarbons and hydrocarbon derivatives containing oxygen,nitrogen,chlorine,bromine and sulfur,are given.Compared with the predictions,results made use of the most common existing group contribution methods,the overall average absolute difference of boiling point predictions of 417 organic compounds is 4.2 K;and the average absolute percent derivation is 1.0%,which is compared with 12.3 K and 3.2% with the method of Joback,12.1 K and 3.1% with the method of Constantinou-Gani.This new position contribution groups method is not only much more accurate but also has the advantages of simplicity and stability. 展开更多
关键词 normal boiling point PREDICTION position group contribution
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INTERSECTION POINT RULE OF THE RETENTION VALUE AND NORMAL BOILING POINT OF THE HOMOLOGUES IN REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY 被引量:1
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作者 Fu An WANG Chang Sheng YANG +1 位作者 Wen Chang WANG Yuan Li JIANG 《Chinese Chemical Letters》 SCIE CAS CSCD 1991年第8期637-640,共4页
In this paper, a linear relationship between the logarithm of capacity factor k and normal boiling point to of the homologues has been derived, based on the basic retention equation of liquid chromatography according ... In this paper, a linear relationship between the logarithm of capacity factor k and normal boiling point to of the homologues has been derived, based on the basic retention equation of liquid chromatography according to statistical thermodyoamics proposed by professor Ln Peizhang and others, This equation has been verified by a large number of experimental data, all the strsight lines of lnk- of bumologues for different mobile phass coaiposltion cross each other at the same point, So the intereection point equation van proposed, wbich was used to prodict the retention valu, the result was satisfactory. 展开更多
关键词 BURR INTERSECTION point RULE OF THE RETENTION VALUE AND normal BOILING point OF THE HOMOLOGUES IN REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY
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Structural Vector Description and Estimation of Normal Boiling Points for 66 Aromatic Hydrocarbons
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作者 Shu Shen LIU Chun Sheng YIN +1 位作者 Shao Xi CAI Zhi Liang LI 《Chinese Chemical Letters》 SCIE CAS CSCD 2000年第12期1089-1092,共4页
A molecular vector-type descriptor containing 6 variables is used to describe the structure of aromatic hydrocarbons (AHs) and relate to normal boiling points (bp) of AHs. The col relation coefficient (R) between the ... A molecular vector-type descriptor containing 6 variables is used to describe the structure of aromatic hydrocarbons (AHs) and relate to normal boiling points (bp) of AHs. The col relation coefficient (R) between the estimated bp and experimental bp is 0.9988 and the root mean square error (RMS) is 7.907 degreesC for 66 AHs. The RMS obtained by cross-validation is 9.131 degreesC, which implies the relationship model having good prediction ability. 展开更多
关键词 molecular vector-type descriptor aromatic hydrocarbon normal boiling point
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Evaluation of the Performance of the GSSM Under Vibration Based on Normalized Point Source Sensitivity
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作者 Qichang An Jingxu Zhang +1 位作者 Fei Yang Hongchao Zhao 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2017年第5期82-87,共6页
Giant Steerable Science Mirror( GSSM) is the tertiary mirror of the Thirty Meter Telescope( TMT).To evaluate the performance of the GSSM under the mechanical vibration,the Normalized Point Source Sensitivity( PSSn) is... Giant Steerable Science Mirror( GSSM) is the tertiary mirror of the Thirty Meter Telescope( TMT).To evaluate the performance of the GSSM under the mechanical vibration,the Normalized Point Source Sensitivity( PSSn) is used to understand and characterize the optical performance degradation. First and foremost,the definition of the PSSn is shown and the calculation procedure of the PSSn at the work condition where the telescope aberration is much smaller than seeing is presented to reveal the relationship between PSSn and seeing.Then,the optical degradation due to vibration is achieved by the two methods: one is the statistics moment for the arbitrary froms of vibration and other one is spectrum method for wind load. After the theoretical presence,the simulation is processed. The multi-axis-accelerometers are used to achieve the motion of the mirror. After integrated to displacement signal,the measured signal is applied to the mathematical model of the GSSM and the optical performance degradation under certain mechanical vibration can be achieved. The PSSN flows from 0.996 to 0.994 under some dynamic vibration. And then,the wind load is applied to the mathematical model using spectrum method with the PSSN flows from 0.996 to 0.991. This paper can help the system engineers to predict the performance of the GSSM in various work condition. What is more,PSSn is able to be combined just by simple multiplication,so the optical performance degradation can be easily co-considered with other error sources. 展开更多
关键词 Thirty METER TELESCOPE normalized point SOURCE Sensitivity optical TRANSFER function mechanical VIBRATION
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Normality Criteria of Meromorphic Functions Concerning Shared Fixed-points 被引量:1
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作者 杨祺 《Chinese Quarterly Journal of Mathematics》 2015年第1期20-29,共10页
In this paper, we study the normality criteria of meromorphic functions concerning shared fixed-points, we obtain: Let F be a family of meromorphic functions defined in a domain D. Let n, k ≥ 2 be two positive intege... In this paper, we study the normality criteria of meromorphic functions concerning shared fixed-points, we obtain: Let F be a family of meromorphic functions defined in a domain D. Let n, k ≥ 2 be two positive integers. For every f ∈ F, all of whose zeros have multiplicity at least (nk+2)/(n-1). If f(f(k))nand g(g(k))nshare z in D for each pair of functions f and g, then F is normal. 展开更多
关键词 meromorphic function FIXED-pointS shared value normal criterion
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New Normal Control of Agricultural Non-point Source Pollution in the Dianchi Lake Basin 被引量:9
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作者 Xia Tiyuan Chen Zebin Jin Song 《Meteorological and Environmental Research》 CAS 2017年第2期63-72,共10页
Based on Kunming statistical yearbook and field survey data of agricultural non-point source pollution in counties or districts in the Dianchi Lake basin,previous and current situation of agricultural production and a... Based on Kunming statistical yearbook and field survey data of agricultural non-point source pollution in counties or districts in the Dianchi Lake basin,previous and current situation of agricultural production and agricultural non-point source pollution control in the Dianchi Lake basin were studied,and countermeasures and suggestions of comprehensive control of agricultural non-point source pollution in the basin were proposed. 展开更多
关键词 The Dianchi LAKE BASIN AGRICULTURAL non-point source POLLUTION NEW normal control Measures China
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Point Transformations and Relationships among Linear Anomalous Diffusion, Normal Diffusion and the Central Limit Theorem 被引量:1
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作者 Donald Kouri Nikhil Pandya +2 位作者 Cameron L. Williams Bernhard G. Bodmann Jie Yao 《Applied Mathematics》 2018年第2期178-197,共20页
We present new connections among linear anomalous diffusion (AD), normal diffusion (ND) and the Central Limit Theorem (CLT). This is done by defining a point transformation to a new position variable, which we postula... We present new connections among linear anomalous diffusion (AD), normal diffusion (ND) and the Central Limit Theorem (CLT). This is done by defining a point transformation to a new position variable, which we postulate to be Cartesian, motivated by considerations from super-symmetric quantum mechanics. Canonically quantizing in the new position and momentum variables according to Dirac gives rise to generalized negative semi-definite and self-adjoint Laplacian operators. These lead to new generalized Fourier transformations and associated probability distributions, which are form invariant under the corresponding transform. The new Laplacians also lead us to generalized diffusion equations, which imply a connection to the CLT. We show that the derived diffusion equations capture all of the Fractal and Non-Fractal Anomalous Diffusion equations of O’Shaughnessy and Procaccia. However, we also obtain new equations that cannot (so far as we can tell) be expressed as examples of the O’Shaughnessy and Procaccia equations. The results show, in part, that experimentally measuring the diffusion scaling law can determine the point transformation (for monomial point transformations). We also show that AD in the original, physical position is actually ND when viewed in terms of displacements in an appropriately transformed position variable. We illustrate the ideas both analytically and with a detailed computational example for a non-trivial choice of point transformation. Finally, we summarize our results. 展开更多
关键词 Generalized Fourier Analysis normal DIFFUSION ANOMALOUS DIFFUSION point TRANSFORMATIONS CANONICAL Quantization Super Symmetric Quantum Mechanics
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基于波形相似性的柔性互联配电网短路故障区段定位方法
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作者 陈继明 陈文淙 +2 位作者 仉志华 于馨玮 徐乾 《电力工程技术》 北大核心 2025年第1期104-114,共11页
由于柔性多状态开关(soft normal open point,SNOP)复杂的控制策略及其弱馈特性,传统配电网故障定位方法难以适用于柔性互联配电网(flexible distribution network,FDN)。因此,文中提出一种利用电流正序分量波形相似性进行FDN故障区段... 由于柔性多状态开关(soft normal open point,SNOP)复杂的控制策略及其弱馈特性,传统配电网故障定位方法难以适用于柔性互联配电网(flexible distribution network,FDN)。因此,文中提出一种利用电流正序分量波形相似性进行FDN故障区段定位的方法。首先,针对SNOP的典型控制策略,分析FDN的短路故障特征。其次,计算配电网中不同故障位置电流正序分量的Tanimoto系数,通过对比不同位置的电流正序分量波形相似性,构建FDN短路故障定位判据,并通过Teager能量算子(Teager energy operation,TEO)实现故障时刻的精确定位,利用智能配电终端(smart terminal unit,STU)传递信息。最后,通过建模仿真对所提方法进行分析验证,结果表明该方法能够对故障区段进行准确定位,不受故障位置、故障类型、过渡电阻、采样频率及通信延时等因素的影响,验证了该方法的可行性与有效性。 展开更多
关键词 柔性互联配电网(FDN) 柔性多状态开关(SNOP) 故障分析 波形相似性 故障定位 电流正序分量
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Feature detection on point clouds via Gabriel Triangles creation and l1 normal reconstruction 被引量:1
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作者 ZHANG Shaoguang WANG Xiaochao +1 位作者 CAO Junjie WANG Jun 《Computer Aided Drafting,Design and Manufacturing》 2012年第4期29-35,共7页
In this paper, we present a robust subneighborhoods selection technique for feature detection on point clouds scattered over a piecewise smooth surface. The proposed method first identifies all potential features usin... In this paper, we present a robust subneighborhoods selection technique for feature detection on point clouds scattered over a piecewise smooth surface. The proposed method first identifies all potential features using covariance analysis of the local- neighborhoods. To further extract the accurate features from potential features, Gabriel triangles are created in local neighborhoods of each potential feature vertex. These triangles tightly attach to underlying surface and effectively reflect the local geometry struc- ture. Applying a shared nearest neighbor clustering algorithm on ~ 1 reconstructed normals of created triangle set, we classify the lo- cal neighborhoods of the potential feature vertex into multiple subneighborhoods. Each subneighborhood indicates a piecewise smooth surface. The final feature vertex is identified by checking whether it is locating on the intersection of the multiple surfaces. An advantage of this framework is that it is not only robust to noise, but also insensitive to the size of selected neighborhoods. Ex- perimental results on a variety of models are used to illustrate the effectiveness and robustness of our method. 展开更多
关键词 feature detection point clouds subneighborhoods selection Gabriel triangles creation l1 normal reconstruction
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Protocol for the management of oral surgery patients on warfarin utilizing a Point-of-Care In-Office international normalized ratio monitoring device 被引量:1
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作者 Gregory P. Hatzis 《Open Journal of Stomatology》 2013年第4期255-267,共13页
Purpose: This study was performed to assess the utility and safety of an In-Office INR Monitoring Device and present a safe and efficient protocol for the management of patients on oral anticoagulants and/or antithrom... Purpose: This study was performed to assess the utility and safety of an In-Office INR Monitoring Device and present a safe and efficient protocol for the management of patients on oral anticoagulants and/or antithrombolytics requiring routine office oral and maxillofacial surgery. Patients and Methods: Sixty-one patients requiring “minor” oral and maxillofacial surgery being treated chronically with oral anticoagulation (warfarin) were entered into the study and compared in 2 groups. The control group (n = 29) was managed by discontinuing warfarin and any anti-platelet medication(s) prior to surgery. In the study group (n = 30), the decision to continue or withhold warfarin was determined by a protocol in which patients are 1) stratified based on risk for thromboembolism, and 2) classified as requiring “major” or “minor” surgery. Procedures categorized as “minor” surgery included dental extraction(s), dental implants, soft tissue and bone biopsies, and preprosthetic bone surgery, and incision and drainage. Warfarin and antiplatelet medication were not withheld in these patients, and a Point-of-Care In-Office INR Monitoring Device was used to obtain INR levels on the day of consultation and surgery. Local measures including removal of granulation tissue, packing, suturing, etc. were utilized for hemostasis. Results: The 30 patients in the study group maintained on warfarin readily achieved hemostasis using intraoperative local measures. The mean INR measured by the In-Office INR Monitoring Device was 2.36 with a range from 1.3 to 3.2. Study group patients underwent a total of 131 separate procedures including 108 dental extractions (impactions), placement of dental implants, preprosthetic bony surgery, bone cyst removal, soft tissue biopsies, facial skin cancer repair, and incision and drainage. One patient (3%) required “minor” intervention with removal of a “liver clot” on postop day 2 with repacking and suturing. The 29 patients in the control group discontinued off of war farin underwent a total of 99 procedures. One patient (3%) also required a “minor” intervention (repacking of extraction site). There were no “major” complications in either group. Conclusions: This study supports previous studies that minor oral surgery procedures can be safely performed while maintaining patients on warfarin minimizing the risk of a potentially devastating thromboembolic event. When deciding whether or not to withhold warfarin, this study supports the use of the proposed protocol based on 1) risk stratification for thromboembolism, 2) the need for “minor” versus “major” surgery, 3) and utilization of an In-Office INR Monitoring Device. An In-Office Point-of-Care INR measuring device can be a very effective tool to safely simplify and make the perioperative management of the anticoagulated patient more efficient for the patient and oral and maxillo facial surgeon. 展开更多
关键词 point-OF-CARE In-Office INR International normalized Ratio THROMBOEMBOLISM Perioperative Care Anticoagulated ORAL and Maxillofacial SURGERY Extraction Warfarin Coumadin ORAL SURGERY
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融合法向信息和尺度自适应的稳健点云平面拟合方法
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作者 吴颖 彭警 刘小生 《大地测量与地球动力学》 北大核心 2025年第2期116-119,共4页
为解决现有稳健拟合算法在高污染率点云数据中容易失效的问题,在基于特征值分解的平面拟合方法中引入权阵,根据点云的法向量确定权重初值,初步降低粗差的影响。然后使用尺度自适应方法增强算法的稳健性,其尺度因子随迭代次数的增加逐步... 为解决现有稳健拟合算法在高污染率点云数据中容易失效的问题,在基于特征值分解的平面拟合方法中引入权阵,根据点云的法向量确定权重初值,初步降低粗差的影响。然后使用尺度自适应方法增强算法的稳健性,其尺度因子随迭代次数的增加逐步减小,可有效解决传统M估计崩溃率低的问题。实验结果表明,本文算法的崩溃率高于已有的稳健点云拟合方法,能够在粗差比例高的点云数据中准确估计平面参数。 展开更多
关键词 加权特征值法 法向信息 尺度自适应 稳健点云平面拟合
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基于三维正态分布变换改进算法的移动机器人实时定位
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作者 赵卫东 吕红兵 +1 位作者 刘立磊 周大昌 《安徽工业大学学报(自然科学版)》 2025年第1期46-53,共8页
针对点云配准三维正态分布变换(3D-NDT)在未确定初始位姿情况下配准精度较低、配准时间较长,无法满足移动机器人实时定位要求,提出1种改进的3D-NDT点云配准融合算法。在原始点云的降采样过程中,使用源点云中的点替代计算得到的重心,降... 针对点云配准三维正态分布变换(3D-NDT)在未确定初始位姿情况下配准精度较低、配准时间较长,无法满足移动机器人实时定位要求,提出1种改进的3D-NDT点云配准融合算法。在原始点云的降采样过程中,使用源点云中的点替代计算得到的重心,降低算法运算量并保留点云的特征信息;通过引入信赖半径动态调节迭代步长,提高降采样后的精度和点云配准速度;通过融合三维激光点云数据与9轴惯性测量单元(IMU)数据,解决2组点云数据位姿差异过大无法收敛或进入局部极值的问题。采用实验室自搭建的移动机器人平台对改进的3D-NDT算法进行仿真实验,验证改进算法实时定位的可靠性和准确度。结果表明:与传统3D-NDT算法相比,改进3D-NDT算法在室外和室内环境下的匹配精度分别提升106%,108%,匹配成功率分别提升8.29%,6.35%,平均匹配耗时分别降低51.1%,47.9%,移动机器人实时定位的配准精度得到较大提升,单次配准时间也大幅降低,改进的3D-NDT算法可满足移动机器人实时定位的需求。 展开更多
关键词 正态分布变换 点云数据 点云配准 惯性测量单元(IMU) 数据融合 动态信赖半径 自主定位 移动机器人
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考虑能量转换装置可变效率的综合能源系统多目标优化调度
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作者 姜延卓 高冲 +4 位作者 刘艳云 张真理 叶荣江 李万彬 谢庆 《电力系统保护与控制》 北大核心 2025年第1期71-83,共13页
为了全面考虑综合能源系统的运行性能,提出一种计及能量转换装置可变效率的综合能源系统多目标优化运行方法。首先,对具有可变效率的能量转换设备运行特性曲线进行分段线性化处理。其次,建立以经济成本、碳排放量和综合能源利用效率为... 为了全面考虑综合能源系统的运行性能,提出一种计及能量转换装置可变效率的综合能源系统多目标优化运行方法。首先,对具有可变效率的能量转换设备运行特性曲线进行分段线性化处理。其次,建立以经济成本、碳排放量和综合能源利用效率为优化对象的多目标优化调度模型,并通过Charnes-Cooper变换解决综合能源利用效率目标的非凸非线性问题。最后,在求解该多目标模型时,运用规格化法平面约束法生成均匀分布的帕累托前沿,再采用改进熵权双基点法决策出折衷最优解。对修改的IEEE 33节点电网和8节点热网耦合的综合能源系统进行仿真分析。结果表明:优化后的模型和算法可以得到兼顾综合能源系统经济性、低碳性及高效性的优化运行方案,为决策者提供科学的决策参考。 展开更多
关键词 综合能源系统 多目标优化 可变效率 规格化法平面约束法 改进熵权双基点法
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Common Fixed Points under Contractive Conditions in Cone Metric Spaces 被引量:1
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作者 WANG Yun-jie ZHU Jiang 《Chinese Quarterly Journal of Mathematics》 CSCD 2013年第1期47-52,共6页
In order to develop and improve the fixed point theorems in cone metric spaces, some new fixed point theorems are presented for two mappings in cone metric spaces which satisfy contractive conditions, where the cone i... In order to develop and improve the fixed point theorems in cone metric spaces, some new fixed point theorems are presented for two mappings in cone metric spaces which satisfy contractive conditions, where the cone is not necessarily normal. Our results generalize fixed point theorems of Abbas, Jungck and Stojan Radenovi in cone metric spaces. 展开更多
关键词 cone metric space normal and non-normal cone common fixed point
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New Common Fixed Point Results for Four Maps on Cone Metric Spaces 被引量:12
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作者 Yan Han Shaoyuan Xu 《Applied Mathematics》 2011年第9期1114-1118,共5页
In this paper, some new existence and uniqueness of common fixed points for four mappings are obtained, which do not satisfy continuity and commutation on non-normal cone metric spaces. These results improve and gener... In this paper, some new existence and uniqueness of common fixed points for four mappings are obtained, which do not satisfy continuity and commutation on non-normal cone metric spaces. These results improve and generalize several well-known comparable results in the literature. 展开更多
关键词 COMMON Fixed point CONE METRIC Space Non-normal CONE
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A new approach to retrieve leaf normal distribution using terrestrial laser scanners 被引量:1
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作者 Shengye Jin Masayuki Tamura Junichi Susaki 《Journal of Forestry Research》 SCIE CAS CSCD 2016年第3期631-638,共8页
Leaf normal distribution is an important structural characteristic of the forest canopy. Although terrestrial laser scanners(TLS) have potential for estimating canopy structural parameters, distinguishing between le... Leaf normal distribution is an important structural characteristic of the forest canopy. Although terrestrial laser scanners(TLS) have potential for estimating canopy structural parameters, distinguishing between leaves and nonphotosynthetic structures to retrieve the leaf normal has been challenging. We used here an approach to accurately retrieve the leaf normals of camphorwood(Cinnamomum camphora) using TLS point cloud data.First, nonphotosynthetic structures were filtered by using the curvature threshold of each point. Then, the point cloud data were segmented by a voxel method and clustered by a Gaussian mixture model in each voxel. Finally, the normal vector of each cluster was computed by principal component analysis to obtain the leaf normal distribution. We collected leaf inclination angles and estimated the distribution, which we compared with the retrieved leaf normal distribution. The correlation coefficient between measurements and obtained results was 0.96, indicating a good coincidence. 展开更多
关键词 Leaf normal distribution Leaf inclinationangle Terrestrial laser scanner point cloud data Curvature - Clustering
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Point Correspondences between <i>N</i>+ 1 Hypersurfaces of Projective Spaces and (<i>N</i>+ 1)-Webs
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作者 V. S. Bolodurin 《Applied Mathematics》 2013年第11期14-22,共9页
For a correspondence in question we establish a sequence of fundamental geometrical objects of the correspondence and find invariant normalizations of the first and second orders of all hupersurfaces under the corresp... For a correspondence in question we establish a sequence of fundamental geometrical objects of the correspondence and find invariant normalizations of the first and second orders of all hupersurfaces under the correspondence. We single out main tensors of the correspondence and establish a connection between the geometry of point correspondences between n + 1 hypersurfaces of projective spaces and the theory of multidimensional (n + 1)-webs. 展开更多
关键词 Hupersurface point CORRESPONDENCE Invariant normalization Multidimensional (n + 1)-Webs
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UNIFORM NORMAL STRUCTURE AND SOLUTIONS OF REICH’S OPEN QUESTION
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作者 曾六川 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2005年第9期1204-1211,共8页
The open question raised by Reich is studied in a Banach space with uniform normal structure, whose norm is uniformly Gateaux differentiable. Under more suitable assumptions imposed on an asymptotically nonexpansive m... The open question raised by Reich is studied in a Banach space with uniform normal structure, whose norm is uniformly Gateaux differentiable. Under more suitable assumptions imposed on an asymptotically nonexpansive mapping, an affirmative answer to Reich' s open question is given. The results presented extend and improve Zhang Shisheng' s recent ones in the following aspects : (i) Zhang' s stronger condition that the sequence of iterative parameters converges to zero is removed; (ii) Zhang' s stronger assumption that the asymptotically nonexpansive mapping has a fixed point is removed; (iii) Zhang' s stronger condition that the sequence generated by the Banach Contraction Principle is strongly convergent is also removed. Moreover, these also extend and improve the corresponding ones obtained previously by several authors including Reich, Shioji, Takahashi,Ueda and Wittmann. 展开更多
关键词 asymptotically nonexpansive mapping fixed point uniform normal structure uniformly CJateaux differentiable norm iterative approximation
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结合超体素与颜色信息的区域生长点云分割方法
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作者 鲁斌 王志远 《计算机工程与设计》 北大核心 2024年第5期1482-1489,共8页
为解决传统区域生长点云分割算法存在的欠分割和过分割现象,提出一种结合超体素与颜色信息的区域生长点云分割方法。在分割过程中加入超体素过分割步骤,避免直接从点云中分割数据,有效消除噪声和异常值对分割的影响,利用一种几何和颜色... 为解决传统区域生长点云分割算法存在的欠分割和过分割现象,提出一种结合超体素与颜色信息的区域生长点云分割方法。在分割过程中加入超体素过分割步骤,避免直接从点云中分割数据,有效消除噪声和异常值对分割的影响,利用一种几何和颜色信息的联合准则合并超体素并进行区域生长。与深度学习方法和其它3种传统分割算法相比,分割效率和精度都得到了较大提升,解决了欠分割和过分割的问题。 展开更多
关键词 超体素 法线信息 点云分割 区域生长 颜色信息 过分割 欠分割
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基于点云和力控的乳腺超声机器人路径规划
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作者 李保坤 张俊超 《兰州工业学院学报》 2024年第6期61-69,共9页
针对B超检查过程中存在的操作规范和疲劳问题,将机器人运动规划及控制技术应用于乳腺超声检查中,减轻操作医师劳动强度、提高检查准确率和筛查效率。针对因自然光不一致导致的成像和重建精度问题,使用红外双目相机平台结合立体匹配算法... 针对B超检查过程中存在的操作规范和疲劳问题,将机器人运动规划及控制技术应用于乳腺超声检查中,减轻操作医师劳动强度、提高检查准确率和筛查效率。针对因自然光不一致导致的成像和重建精度问题,使用红外双目相机平台结合立体匹配算法对女性乳腺模型进行三维重建,提高了乳腺模型点云数据重建精度。依照女性乳腺B超检查规程,提取模型中层点云,针对中层点云乱序问题,通过优化点云后处理过程,对点云法向量方向进行了校正。并将点云按环形排序以生成初步扫描路径;再对路径进行非均匀有理B样条插值处理,使路径光顺化。根据机器人单一视觉控制存在精度和安全性问题,提出通过在执行器末端引入六维力传感器,建立导纳控制模型,实现力反馈柔顺控制,解决了系统精度和安全性问题。通过仿真验证及实验模拟表明,该系统在扫描过程中提高了人身安全性。研究模拟人工手眼协调进行乳腺超声安全检查,可对实施基于机器人技术的乳腺癌大规模筛查提供必要技术支撑。 展开更多
关键词 三维重建 点云法向量 点云后处理 路径规划 力反馈控制
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