IMPROVEMENTS IN HIDDEN LINE REMOVAL ALGORITHM FOR BI-PARAMETRIC SURFACES

A hidden line removal algorithm for bi parametric surfaces is presented and illustrated by some experimental results. The enclosure test is done using area coordinates. A technique of moving box of encirclement is presented. It is found that the algorithm is of general purpose, requires minimal computer storage, has high accuracy and simplicity, and is very easy to be implemented on a computer.

Labeling Line Drawings with Hidden-Part-Drawn of Planar Object with Trihedral Vertices

Although line drawings consist of only line segments on a plane, they convey much information about the three-dimensional object structures. For a computer interpreting line drawings, some intelligent mechanism is required to extract three-dimensional information from the two-dimensional line drawings. In this paper, a new labeling theory and method are proposed for the two-dimensional line drawing with hidden-part-draw of a three-dimensional planar object with trihedral vertices. Some rules for labeling line drawing are established. There are 24 kinds of possible junctions for line drawing with hidden-part-draw, in which there are 8 possible Y and 16 W junctions. The three problems are solved that Sugihara＇s line drawing labeling technique exists. By analyzing the projections of the holes in manifold planar object, we have put forward a labeling method for the line drawing. Our labeling theory and method can discriminate between correct and incorrect hidden-part-draw natural line drawings. The hidden-part-draw natural line drawings can be labeled correctly by our labeling theory and method, whereas the labeling theory of Sugihara can only label the hidden-part-draw unnatural line drawings in which some visible lines must be drawn as hidden lines, and some invisible lines must be drawn as continuous lines.

The on-line direct fitting of low signal-noise ratio single ion channel recordings based on hidden Markov models

Many kinds of channel currents are especially weak and the background noise dominates in the patch clamp recordings. This makes the threshold detection fail during estimating of the transition probabilities. So direct fitting of the patch clamp recording, not of the histogram coming from the recordings, is a desirable way to estimate the transition probabilities. Iterative batch EM algorithm based on hidden markov model has been used in this field but which has the "curse of dimensionality" and besides cant keep tracking the varying of the parameters. A new on line sequential iterative one is proposed here, which needs fewer computational efforts and can adaptively keep tracking the varying of parameters. Simulations suggest its robust, effective and convenient.

A Fast Hidden-line Removal Algorithm for 3-Dimensional Buildings

in this paper, a fast hidden-line removal method for 3D buildings , which is based on thesubtraction of a convex polygon from another one in linear time, is presented. Also, the facetscontaining holes are quickly divided into a lot of convex polygons, say, triangles and convexquadrilaterals. The algorithm for the polygon division runs in O( (k+1) (n-3)) , where n is thetotal number of the vertices of the merged loop of the facet, and k is the number of the concavevertices of the merged one.

Multi-scroll hidden attractors and multi-wing hidden attractors in a 5-dimensional memristive system

A novel 5-dimensional（5D） memristive chaotic system is proposed, in which multi-scroll hidden attractors and multiwing hidden attractors can be observed on different phase planes. The dynamical system has multiple lines of equilibria or no equilibrium when the system parameters are appropriately selected, and the multi-scroll hidden attractors and multi-wing hidden attractors have nothing to do with the system equilibria. Particularly, the numbers of multi-scroll hidden attractors and multi-wing hidden attractors are sensitive to the transient simulation time and the initial values. Dynamical properties of the system, such as phase plane, time series, frequency spectra, Lyapunov exponent, and Poincar′e map, are studied in detail. In addition, a state feedback controller is designed to select multiple hidden attractors within a long enough simulation time. Finally, an electronic circuit is realized in Pspice, and the experimental results are in agreement with the numerical ones.

Detection of Drought-Related Loci in Rice at Reproductive Stage Using Selected Introgressed Lines

The present study was carried out to illustrate high-efficient detection of quantitative trait loci （QTLs） with selected introgression lines （ILs） and the existence of ＇hidden genes＇ conferring drought tolerance （DT）. 52 selected DT ILs, derived from BC2Fz population developed by crossing and backcrossing the susceptible recurrent parent （RP） IR64 with the susceptible donor Khazar were planted under irrigation and drought condition. Four important agronomic traits, e.g., grain yield （GY）, heading date （HD）, panicle numbers per plant （PN）, and plant height （PH） were evaluated and 83 SSR polymorphic molecular markers were used for genotypic analysis. Chi-square test based on genetic hitch-hiking and one-way analysis of variances （ANOVA） were used to detect drought-related loci. Nine and 36 loci were detected by chi-square test and one-way ANOVA, respectively. Five common loci were observed by comparing the results of the two methods, among which two QTLs linked with RM7, and RM241 were detected under irrigation condition, both of the favorable alleles were from RP and explained 13% phenotypic variation （PV） for GY and 28% PV for PH, respectively. The other three QTLs linked with RM 163, RM 18, and RM270 were detected under drought condition, the favorable alleles were all from the donor and explained 10, 24, and 19% PV for HD, PH, and PH, respectively. Five common loci were observed by comparing the results of chi-square test and one-way ANOVA including two QTLs （one for GY and one for PH） under irrigation condition and three QTLs （one for HD and two for PH） under drought condition. By combining phenotypic and genotypic analysis, drought escape could be inferred as the main mechanism for drought tolerance in the present study. The results in present study suggested that the selected ILs population analyzed by chi-square test and one-way ANOVA was quite effective for DT QTL detection with low inputs and could also produce useful materials for breeding with wide genetic diversity for drought tolerance.

3D Reconstruction from 2D Line Drawings only with Visible Vertices and Edges

The human vision system can reconstruct a 3D object easily from single 2D line drawings even if the hidden lines of the object are invisible. Now, there are many methods have emulated this ability, but when the hidden lines of the object are invisible, these methods cannot reconstruct a complete 3D object. Therefore, we put forward a new algorithm to settle this hard problem. Our approach consists of two steps： （1） infer the invisible vertices and edges to complete the line drawing, （2） propose a vertex-based optimization method to reconstruct a 3D object.

Einstein’s Non-Euclidean Line Element Theory and Quantum Mechanics Interpretation

In “The third speech on the wave mechanics” (1926), E. Schodinger pointed that the Hamilton-Maupertuis principle as a classical starting point of wave mechanics in the definition of generalized coordinate space line element, introduced the generalized non-Euclidean geometry, and finally obtained the wave equation including Laplace operator in the generalized non Euclidean geometry line element. At the 1927 meeting of the Prussian Academy of Sciences in Berlin, Albert Einstein read a paper entitled “Does Schodinger’s wave mechanics determines the dynamics of a system’s movement completely or only sence in statistics?”. In this paper, Einstein used the Schodinger equation to obtain a representation of the kinetic energy, and used the non-Euclidean line element of the Configuration space to define the velocity component of a single particle, and return to determinism. But Bothe pointed out that when people considered a system composed of two subsystems, the wave function of the whole system can be decomposed into two simple products of the wave function of the two subsystems, but the hidden variables are dependent on each other. Einstein be-lieved that this was not acceptable, gave up the publication of the paper on the non-European line hidden variables theory. In the long-term controversy with the Copenhagen school, Einstein was convinced that the probability interpretation of the wave function was indispensable because of the incompleteness of quantum mechanics, but not the wave function probability led to the incompleteness of quantum mechanics. Any attempt to seek a complete explanation of quantum mechanics is inevitable to change the current formal system of quantum mechanics.

Locating the position of objects in non-line-of-sight based on time delay estimation

Non-line-of-sight imaging detection is to detect hidden objects by indirect light and intermediary surface（diffuser）.It has very important significance in indirect access to an object or dangerous object detection, such as medical treatment and rescue. An approach to locating the positions of hidden objects is proposed based on time delay estimation. The time delays between the received signals and the source signal can be obtained by correlation analysis, and then the positions of hidden objects will be located. Compared with earlier systems and methods, the proposed approach has some modifications and provides significant improvements, such as quick data acquisition, simple system structure and low cost, and can locate the positions of hidden objects as well： this technology lays a good foundation for developing a practical system that can be used in real applications.

探地雷达法在水工隧洞衬砌隐蔽缺陷检测中的应用

水工隧洞衬砌施工过程中易产生隐蔽性缺陷,危害隧洞的安全稳定运行,因此同步开展检测对保证施工质量具有重要作用。探地雷达法属于当前较为先进的混凝土质量原位检测技术,根据该方法基础原理和数据采集及处理方法,以新疆某水利枢纽为例分析研究该方法在中孔溢洪洞衬砌质量检测中的具体应用,结果表明,探地雷达法可通过研究电磁波在衬砌结构体内传播特征对隐蔽性缺陷进行无损、经济、高效检测,可为指导后续处理方案设计提供科学的数据服务和决策支持。

基于潮流相关性网络的电网脆弱线路识别

国内外大停电事故表明,电力系统中的脆弱线路会带来极大的运行风险,直接导致系统安全性下降.鉴于此,本文根据二级连锁故障发生时有功潮流的转移特征进行电力系统脆弱线路识别.首先,从系统运行角度,以电力系统发生二级连锁故障时有功潮流的转移量为系统线路间关系进行赋权,并构建双向加权潮流相关性网络;随后,为量化线路在连锁故障中的脆弱性,提出一种基于改进E指数的脆弱线路识别方法.研究表明:针对IEEE-39节点系统,依据本文方法识别结果中前8条脆弱线路的平均风险价值指数和平均条件风险价值指数分别为3 453.73 MW与187.82 MW,远高于其他方法所得结果;静态蓄意攻击后所得的系统剩余负荷率仅为43.4%,系统子电气岛数量快速增长.

基于无人机激光点云的电力线路树障隐患预测技术分析

为解决无人机激光测距存在的树木隐患排查不全的问题,提出采用激光点云数据实现电力线路树障隐患预测。通过实现电力线点云数据自动提取和分类,完成单木分割分类管理,并建立模型实现数据生长态势预测,能够解决树木畸形生长带来的树障隐患排查难题。研究结果表明,利用贝叶斯估计法对树木生长态势实施科学预测,根据树木和导地线距离精准评估树障隐患风险,能够为解决树障隐患排查问题提供有效技术方案。

配电线路外部隐患自动识别装置自动化控制系统

为了提升系统稳定性并降低故障率,基于多模块架构设计配电线路外部隐患自动识别装置自动化控制系统。该系统采用双目摄像头模块,集成三CMOS传感器与三模冗余容错控制,确保图像采集的可靠性与容错性。控制模块实施双控制器与双机热备技术,保障控制连续性。数据分析模块融合结构相似性指数(SSIM)图像评估与YOLOv3模型,高效识别隐患。实验结果表明,该系统在传感器与控制器故障情况下,展现出优异的稳定性、容错能力及隐患识别精度,有效提升了配电线路安全监测水平。

RESEARCH OF THE PARAMETRIC ASSEMBLY METHOD

The parametric part assembly generation method is presented. Based on the parametric part generated by means of constructive-element, through interactively inputting the relationships of the location and the assembly, and by compiling operations like movement and rotation, the assembly drawing is created so as to implement the occurrence of the parameterizations of the assembly and the part drawing. The data structure of the assembly part and the key technologies of hidden line removal in the implementation of assembly process, etc. , are described in detail.

考虑客户用电安全隐患的配电网脆弱线路风险自动预警方法

脆弱线路作为配电网的重要组成部分,是保证电网安全与用户安全的关键环节。为此,从客户用电安全隐患角度出发,提出配电网脆弱线路风险自动预警方法。基于电气介数模型与线路潮流传输最大值,建立有功潮流介数模型,降序排列有功潮流介数,识别脆弱线路。利用脆弱线路形成最小风险的目标函数模型来评估风险,依据风险期望值与控制决策,划分风险评估等级与预警等级,采用神经网络模型,实现风险自动预警。实验结果表明,所提方法的脆弱线路识别结果与风险自动预警效果较好,能够正确作出风险预警,且实践优势显著。

既有高速铁路接触网供电线电缆改架空工程实践

带有隐蔽工程性质的接触网供电线27.5 kV高压电缆,在敷设安装不规范的情况下存在安全隐患,对供电可靠性造成威胁。本文结合现场实际条件,对电缆进行隐患整治,将隐患电缆改造为架空线,从方案分析论证、线路走向和布置、关键工艺优化等方面进行归纳总结,为高速铁路类似改造施工提供参考。

基于时空演化的输电线通道树竹放电预警方法

为解决输电线通道中树竹放电预警准确率低的问题,提出了一种基于时空演化的输电线通道树竹放电预警方法。首先,通过无人机巢采集输电线通道图像,并进行图像噪声过滤;其次,通过树竹皮、叶子的边缘特征识别树竹类型,并结合典型树竹生长速度和观测的实际生长速度进行时空演化分析,预测树竹放电隐患时间并预警;最后,在某地市供电公司的输电工区进行仿真验证,该方法的树竹放电隐患预警准确率为98.9%,算例的仿真结果表明,所提方法可准确识别输电线通道树竹放电隐患,提升输电线通道的运行维护管理水平。

矿井通风系统巷道自动绘制方法研究

基于使用计算机自动绘制矿井通风系统图的需要,利用面向对象的程序设计思想,设计通风系统巷道的自动绘制算法,提出多条巷道连接于一点的处理方法,引入多条巷道在空间交叉的消隐方法。该算法在孔庄矿局部通风系统中进行了应用,结果表明,能一次性、连续、准确、快速地绘制出井下所有的通风巷道。

电网连锁故障的事故链搜索模型及策略研究

连锁故障是导致大停电事故发生的主要原因,而少数关键线路对连锁故障的发生、发展具有推波助澜的作用。为在模拟连锁故障发展的基础上识别这些关键线路并探究其对连锁故障的影响程度,基于电力系统分析理论和复杂网络理论,提出一种新的连锁故障事故链搜索策略。该方法首先定义关键线路所应具有的特性,进而建立关键线路搜索的数学模型并给出基于遗传算法的求解策略。在此基础上,建立包括后续故障搜索模型和事故链评价指标在内的连锁故障事故链搜索框架。其中,后续故障搜索模型由线路停运模型和关键线路集合两部分组成。最后,以IEEE 10机39节点系统为算例进行仿真,结果验证了所提模型及算法的有效性。

立体几何教学软件中的一个线消隐算法

立体几何教学软件要求场景中的几何体具有真实感,几何体被遮挡的边要随着视点的改变动态地以虚线形式输出,这与传统黑板教学中教师将几何体被遮挡的边画成虚线是一致的,符合学生的学习习惯,易于理解和接受。对三维立体场景中有名的线消隐算法——Roberts算法进行了研究并作了改进,在提高效率的同时将它与一定的数据结构相结合,实现了一种满足立体几何教学软件中把隐藏线以虚线形式输出的特殊要求的线消隐算法。经测试证明此算法是完全可行的。