Position Group Contribution Method for Predicting the Normal Boiling Point of Organic Compounds

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.

INTERSECTION POINT RULE OF THE RETENTION VALUE AND NORMAL BOILING POINT OF THE HOMOLOGUES IN REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

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.

Structural Vector Description and Estimation of Normal Boiling Points for 66 Aromatic Hydrocarbons

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.

Evaluation of the Performance of the GSSM Under Vibration Based on Normalized Point Source Sensitivity

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.

Normality Criteria of Meromorphic Functions Concerning Shared Fixed-points

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.

New Normal Control of Agricultural Non-point Source Pollution in the Dianchi Lake Basin

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.

Point Transformations and Relationships among Linear Anomalous Diffusion, Normal Diffusion and the Central Limit Theorem

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.

结合超体素与颜色信息的区域生长点云分割方法

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。

Feature detection on point clouds via Gabriel Triangles creation and l1 normal reconstruction

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.

Protocol for the management of oral surgery patients on warfarin utilizing a Point-of-Care In-Office international normalized ratio monitoring device

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.

Robust Radiometric Normalization of the near Equatorial Satellite Images Using Feature Extraction and Remote Sensing Analysis

Relative radiometric normalization (RRN) minimizes radiometric differences among images caused by inconsistencies of acquisition conditions rather than changes in surface. Scale invariant feature transform (SIFT) has the ability to automatically extract control points (CPs) and is commonly used for remote sensing images. However, its results are mostly inaccurate and sometimes contain incorrect matching caused by generating a small number of false CP pairs. These CP pairs have high false alarm matching. This paper presents a modified method to improve the performance of SIFT CPs matching by applying sum of absolute difference (SAD) in a different manner for the new optical satellite generation called near-equatorial orbit satellite and multi-sensor images. The proposed method, which has a significantly high rate of correct matches, improves CP matching. The data in this study were obtained from the RazakSAT satellite a new near equatorial satellite system. The proposed method involves six steps: 1) data reduction, 2) applying the SIFT to automatically extract CPs, 3) refining CPs matching by using SAD algorithm with empirical threshold, and 4) calculation of true CPs intensity values over all image’ bands, 5) preforming a linear regression model between the intensity values of CPs locate in reverence and sensed image’ bands, 6) Relative radiometric normalization conducting using regression transformation functions. Different thresholds have experimentally tested and used in conducting this study (50 and 70), by followed the proposed method, and it removed the false extracted SIFT CPs to be from 775, 1125, 883, 804, 883 and 681 false pairs to 342, 424, 547, 706, 547, and 469 corrected and matched pairs, respectively.

基于点云数据的大曲率工件表面法向计算方法研究

航空航天构件装配制孔时对垂直度有严格要求,采用机器人等自动设备制孔时,为保证垂直度需要对每一个制孔位置的法向进行在位测量。现有的工件表面法向测量方式难以适应大曲率工件表面的测量需求。通过线激光扫描,可以获得反映工件局部表面详细信息的点云数据,在此基础上提出一种大曲率工件表面法向计算方法。首先研究了通过主成分分析(PCA)对局部点云数据进行平面拟合获得曲面法向的方法,然后选取了若干典型曲率,通过仿真生成点云数据,并分析了法向拟合误差的变化规律。通过试验验证了上述方法的有效性,结果表明,当点云选择范围在12mm以下时,直径为50mm的圆柱试验件的法向拟合误差可以保证在0.219°以下。

基于法向量夹角的果树点云配准与枝叶分割方法研究

在实现果园作业全自动化的过程中,亟需直接构建自然环境下果树枝干三维模型的方法。本文通过对自然环境下以不同角度采集的果树点云进行配准,并针对采样一致性(SAC-IA)+迭代最近点(ICP)配准算法在点云配准中耗时较长以及精度不高的问题,结合点云法向量夹角提取源点云和目标点云的特征点,并通过点云法向量夹角的余弦值在源点云和目标点云的特征点中查找待匹配点对的方法,提出了一种基于果树点云待匹配点对的改进SAC-IA+ICP点云配准算法;借助最小包围盒划分的分块技术对配准后的果树点云进行分块,然后利用点云的几何特征,对划分的子块进行枝叶粗分割,最后使用欧氏聚类完成枝叶的精细分割。对比实验结果显示,改进后的SAC-IA+ICP算法在平均旋转误差上相较于原始SAC-IA+ICP算法减少85.44%,配准均方根误差相较于原始SAC-IA+ICP算法减少71.74%,配准时间相较于原始SAC-IA+ICP算法减少97.99%;同时,改进后的SAC-IA+ICP算法在平均旋转误差上相较于SAC-IA+NDT算法减少90.38%,配准均方根误差相较于SAC-IA+NDT算法减少85.39%,配准时间相较于SAC-IA+NDT算法减少98.04%。另外,本文采用的枝叶分割算法能够完成枝叶分割,且相较于人工分割其分割准确度可达94.77%。

联合傅里叶卷积与通道注意力的光场角度重建

光场相机能够同时捕获光线的强度和方向信息,但由于成像传感器尺寸的限制,无法同时获得高空间和角度分辨率的光场图像。提出了一种联合傅里叶卷积和通道注意力的光场角度重建方法,通过使用稀疏光场图像4个边角位置的参考视图,可以间接地重建出密集光场图像。考虑到光场数据的内在4D结构,采用通道级密集快速傅里叶残差卷积块,在空域和频域对光场图像的空间和角度相关性进行建模,然后采用基于全局响应归一化的通道注意块,以实现通道间的自适应融合。此外,还提出了一种改进的视点加权间接合成方法,通过为每个参考视图分配一个置信图,为参考视图之间建立联系以合成更真实的新视图。实验结果表明,相比于现有先进的光场角度重建算法IRVAE,所提方法的重建光场图像质量在自然光场数据集30Scenes,Occlusion和Reflective上的平均PSNR分别提高了0.08,0.13和0.13 dB。所提方法在保证光场角度一致性的前提下取得了清晰的重建结果。

基于三维激光点云数据的电力电缆绝缘缺陷识别

针对电力电缆绝缘缺陷识别精准度较低的问题,提出一种基于三维激光点云数据的电力电缆绝缘缺陷识别方法。利用剪裁法增强原始三维激光点云数据,通过区域生长法与最小二乘法完整获取电缆绝缘材料的三维结构面信息。借助Canny边缘检测方法求解电缆绝缘表面缺陷与内部缺陷边缘信息,自动识别出电力电缆绝缘的缺陷位置及缺陷类别。结果表明,所提方法可以精准识别电缆绝缘表面的划痕缺陷、电缆外屏蔽表面起泡和孔洞缺陷,识别耗时短,鲁棒性较优,具有较高实际应用价值。

基于差动共焦法向测量配准的自由曲面测量方法

针对自由曲面设计坐标系和测量坐标系基准不同带来的测量问题,提出了一种基于差动共焦法向测量配准的自由曲面测量方法。方法利用差动共焦曲线过零点位置与被测点准确对应的特性,实现了对被测点的精确定焦;利用PSD在传感器焦点位置对被测点倾角进行精确测量;根据被测点倾角,利用ICP Point to Plane方法进行点云配准,提高了点云配准精度,显著提升了面形测量精度。经理论分析和初步实验证明,方法测量面形PV值的精度可以达到65nm,RMS值达到10nm,PV值与zygo干涉仪测量结果相差7nm,RMS值相差1nm,测量结果误差较小。该方法为自由曲面面形的高精度测量提供了一种新的技术途径。

基于二维正态分布的无人机激光雷达点云匹配研究

无人机激光雷达点云特征多,一次匹配花时间长,难以进行二次匹配,因此研究基于二维正态分布的无人机激光雷达点云匹配方法。采集无人机激光雷达点云图像,通过旋转平移方法、双边滤波方法对图像预处理,利用二维正态分布算法和动态时间规整算法完成点云特征提取,使用初始变换矩阵估计算法对点云进行粗匹配,再使用近点迭代算法进行点云快速精匹配,通过两次匹配实现无人机激光雷达点云快速匹配。实验结果表明,所提方法的无人机激光雷达点云图像去噪效果好,点云匹配时间短,匹配偏差仅在0.04 m-0.15 m之间,匹配精度达到了相关预期。

含电动汽车的主动配电网多目标分层优化调度

为了协调电动汽车车主和主动配电网2个不同主体之间的利益关系,针对电动汽车接入后主动配电网的优化调度问题,文中提出一种考虑电动汽车充电综合满意度和主动配电网运行效益的多目标分层优化方法。上层模型注重最大化电动汽车车主的充电利益,采用归一化法向约束法求解电动汽车的最优充放电计划,并将其输入下层优化模型。下层模型旨在最大化主动配电网的运行效益,根据电动汽车的充放电计划调整可控分布式电源的输出功率,采用二阶锥松弛转换法和带权极小模理想点法求解该非线性多目标问题。仿真结果表明,所提含电动汽车的主动配电网多目标分层优化方法能够在促使电动汽车充电综合满意度超过0.9的同时,减少有功网损约94.12%、运行成本约30.90%,实现电动汽车车主和主动配电网的双赢。

基于自适应局部邻域条件下的点云匹配

为了应对传统迭代最近点(ICP)算法在处理复杂点云空间特征时,面临噪声干扰和数据缺失等问题导致收敛速度缓慢、配准精度不高以及鲁棒性较差等问题,本文提出了一种基于自适应局部邻域条件下的点云匹配算法。首先,采用体素网格滤波对数据进行预处理,根据不同半径邻域内邻近点的分布情况,定义邻域表面的弯曲程度,在此基础上,充分考虑到法向量分布和邻域曲率特征,从而得到更精确的特征点提取;其次,通过运用最小二乘曲面拟合方法,进一步提取出邻域曲率变化最为显著的特征点,采用快速点特征直方图(FPFH)对特征点进行描述,并通过设定距离阈值的采样一致性算法来匹配相似的特征点对,计算出关键的坐标转换参数,完成初始配准。最后,利用线性最小二乘优化点到面的ICP算法,以实现更精确的配准结果。通过一系列实验对比发现相较于现有的几种配准算法(ICP,SAC-IA+ICP,K4PCS+ICP),在存在噪声干扰和数据缺失的情况下,所提方法的配准准确度平均提高45%,配准速度平均提高38%,充分验证了该方法在应对大数据量、低重叠率点云配准方面具备出色的稳健性能。

基于机载LiDAR数据的单木分割研究

基于机载LiDAR数据进行单木分割,分别讨论了基于冠层高度模型的单木提取方法(FCHM)以及基于归一化点云的单木提取算法(FNPC)。FCHM的分离单木的总正确率的均方根值为0.93,F_Score的均方根值为0.62,FNPC算法分别为0.90和0.56,FCHM算法的精度优于FNPC算法。通过从不同的林相、林型、林分密度的分析得出,在林分密度小于400棵/hm^(2)的单层针叶林中提取效果最好。