Quantitative detection of locomotive wheel polygonization under non-stationary conditions by adaptive chirp mode decomposition

Wheel polygonal wear is a common and severe defect,which seriously threatens the running safety and reliability of a railway vehicle especially a locomotive.Due to non-stationary running conditions(e.g.,traction and braking)of the locomotive,the passing frequencies of a polygonal wheel will exhibit time-varying behaviors,which makes it too difficult to effectively detect the wheel defect.Moreover,most existing methods only achieve qualitative fault diagnosis and they cannot accurately identify defect levels.To address these issues,this paper reports a novel quantitative method for fault detection of wheel polygonization under non-stationary conditions based on a recently proposed adaptive chirp mode decomposition(ACMD)approach.Firstly,a coarse-to-fine method based on the time–frequency ridge detection and ACMD is developed to accurately estimate a time-varying gear meshing frequency and thus obtain a wheel rotating frequency from a vibration acceleration signal of a motor.After the rotating frequency is obtained,signal resampling and order analysis techniques are applied to an acceleration signal of an axle box to identify harmonic orders related to polygonal wear.Finally,the ACMD is combined with an inertial algorithm to estimate polygonal wear amplitudes.Not only a dynamics simulation but a field test was carried out to show that the proposed method can effectively detect both harmonic orders and their amplitudes of the wheel polygonization under non-stationary conditions.

凸F-多边形内部的F-点数

An F-polygon is a simple polygon whose vertices are F-points, which are points of the set of vertices of a tiling of R~2 by regular triangles and regular hexagons of unit edge. Let f(v) denote the least possible number of F-points in the interior of a convex F-polygon K with v vertices. In this paper we prove that f(10) = 10, f(11) = 12,f(12) = 12.

Differences of Polygonal Faults with Irregularly Polygonal Geometries: A Case Study from the Changchang Sag of Qiongdongnan Basin, Northern South China Sea

Polygonal faults(PFs)generally have a classic polygonal geometry in map view.However,under the influence of tectonic faults,diapirs,channels,and slopes,the classic polygonal geometry of PFs is not preserved,demonstrating differences(different characters)in map-view 3D seismic data covering an area of 334km^(2) of the Changchang(CC)sag,are used to document the mapview and cross-sectional characteristics of PFs.These data also help investigate the irregularly polygonal geometries of PFs due to the presence of influence factors,such as transtensional faults,submarine fans,channels,diapirs/gas chimneys,and the basal slope within the lower-middle Miocene strata.Results show that various irregularly polygonal geometries of PFs can be classified into enechelon and arcuate PFs,channel-segmenting and-bounding PFs,radial PFs,and rectangular PFs in map-view.En-echelon and arcuate PFs are induced by transtensional faults and exhibit a unique‘flower’structure in NE-and SE-trending cross-sections in the NW area of the study area.This finding is documented for the first time.Channel-segmenting PFs occur in the(northwest)low-amplitude muddy channel and are inhibited in the(southeast)high-amplitude sandy channel in the SW area.Radial PFs are radially aligned around a gas chimney/diapir containing some high-amplitude anomalies(HAAs)in the middle area.The presence of intrusive sandstones with HAAs along the periphery of the diapirs restricts the occurrence of PFs.Two high-amplitude submarine fans act as a mechanical barrier to the propagation of PFs.Meanwhile,the(moderate)slope in the NE area induces rectangular PFs.Additionally,the geneses of the PFs in the current study are comprehensively discussed.This study adds to our understanding of the differences between PFs with irregularly polygonal geometries.

Differences of polygonal faults related to upper Miocene channels:a case study from the Beijiao sag of Qiongdongnan basin,South China Sea

Deep-water coarse-grained channels are embedded within a polygonal fault tier,and the polygonal faults(PFs)present non-polygonal geometries rather than classic polygonal geometry in plan view.However,PFs present differences when they encounter deep-water(coarse-grained vs.fine-grained)channels with different lithology,which has not been further studied to date.Three-dimensional(3D)seismic data and a drilling well from Beijiao sag of Qiongdongnanbasin,South China Sea were utilized to document the plan view and cross-sectional properties of the PFs and their differences and genetic mechanism were investigated.Results show that,first,PFs can be divided morphologically into channel-segmenting PFs and channel-bounding PFs in plan view.The former virtually cuts or segments the axes of channels in highand low-amplitudes,and the latter nearly parallels the boundaries of the channels.Both are approximately perpendicular to each other.Secondly,channel-bounding PFs that related to low-amplitude channels are much longer than those of high-amplitude ones;channel-segmenting PFs related to low-amplitude channels are slightly longer than the counterparts related to high-amplitude channels.Lastly,the magnitudes(e.g.,heights)of the PFs are proportional to the scales(e.g.,widths and heights)of low-amplitude channels,whereas the magnitudes of the PFs are inversely proportional to the scales of high amplitude channels.Coarse-grained(high amplitude)channels act as a mechanical barrier to the propagation of PFs,whereas fine-grained(low-amplitude)channels are beneficial to the propagation and nucleation of PFs.Additionally,the genetic mechanism of PFs is discussed and reckoned as combined geneses of gravitational spreading and overpressure hydrofracture.The differences of the PFs can be used to reasonably differentiate coarse-grained channels from fine-grained channels.This study provides new insights into understanding the different geometries of the PFs related to coarse-grained and fine-grained channels and their genetic mechanism.

Drag Coefficient of a Non-Convex Polygonal Plate during Free Fall

Waterside creatures or aquatic organisms use a fin or web to generate a thrust force. These fins or webs have a non-convex section, referred to as a non-convex shape. We investigate the drag force acting on a non-convex plate during unsteady motion. We perform the experiment in a water tank during free fall. We fabricate the non-convex plate by cutting isosceles triangles from the side of a convex hexagonal plate. The base angle of the triangle is between 0° to 45°. The base angle is 0 indicates the convex hexagonal thin plate. We estimate the drag coefficient with the force balance acting on the model based on the image analysis technique. The results indicate that increasing the base angle by more than 30° increased the drag coefficient. The drag coefficient during unsteady motion changed with the growth of the vortex behind the model. The vortex has small vortices in the shear layer, which is related to the Kelvin-Helmholtz instabilities.

3D Fractals, Axiom of Algebra (Δn)n = +1

After having laid down the Axiom of Algebra, bringing the creation of the square root of -1 by Euler to the entire circle and thus authorizing a simple notation of the nth roots of unity, the author uses it to organize homogeneous divisions of the limited development of the exponential function, that is opening the way to the use of a whole bunch of new primary functions in Differential Calculus. He then shows how new supercomplex products in dimension 3 make it possible to calculate fractals whose connexity depends on the product considered. We recall the geometry of convex polygons and regular polygons.

Results of Geomagnetic Studies on the Problem of Forecasting Strong Earthquakes in Uzbekistan

The article is devoted to the problem of forecasting strong earthquakes by the geomagnetic method. The geomagnetic method is widely used on this problem in seismically active regions of the world as one of the promising, informative and operational geophysical methods. The results of long-term geomagnetic studies on the problem of forecasting strong earthquakes in Uzbekistan are presented. Geomagnetic studies were carried out on the territories of the Tashkent, Ferghana, and Kyzylkum geodynamic polygons in the epicentral zones of strong earthquakes that occurred. Long-term, medium- and short-term precursors of earthquakes have been identified. Anomalous changes in the geomagnetic field associated with the decline in aftershock activity were also revealed. The dependence between the duration of the manifestation of long-term magnetic precursors and the magnitude of earthquakes is determined. Absolute proton magnetometers MMP-1, MV-01 (Russia), and G-856 (USA) were used to measure the geomagnetic field.

Radio-Anatomical Study of Anterior Variants of the Polygon of Willis

The anterior system of the polygon of Willis plays an anastomotic role between the carotid territories and communicates with the posterior system. It ensures adequate cerebral blood flow in the event of internal occlusion. Its ability to redistribute blood flow depends on its morphology, the presence and size of the vessels that constitute it and their variants, knowledge of which is essential. The morphology of the carotid system is not constant and a number of variants are well recognized with greater hemodynamic importance. In this context, we undertook this work which aims to seek the anatomical variants of the anterior part of the PW;to determine the diameters of the vessels of the latter and to correlate these results with epidemiological data. We carried out a retrospective, descriptive and analytical study over a period of 4 months at Fann University Hospital, targeting patients who had undergone brain MRI with a 3D TOF sequence whatever the indication. Patients with lesions of cerebrovascular pathologies such as ischemia, hemorrhage, aneurysm, arteriovenous malformations or presenting a limited analysis examination due to the presence of kinetic or other artifact, were not included. Demographic data and anatomical variants were studied as well as the measurements of any continuous arterial segment greater than 0.8 mm in diameter. Those less than 0.8 mm in diameter were considered hypoplastic. The C3 segment of the internal carotid arteries, the A1 segment of the anterior cerebral arteries, the anterior communicating artery, constituted our main measurement sites. The sex ratio was 1.06, the mean age of the patients was 43 years ± 17.9 with extremes of 11 and 85 years. The anterior configuration of the polygon was complete in 57.5% representing 50% of men and 65.5% of women, in 56% of subjects under 40 years old and 58% in subjects over 40 years old. We noted a predominance of type a in 47% of patients followed by type g found in 35% of patients. The morphology of the anterior system of the Willis polygon is a function of its variants, some of which have greater hemodynamic importance than others. Its knowledge is essential for the management of cerebrovascular diseases.

一种汽车3D UI中带光影贴图车模的制作方法

汽车界面经历了从机械按键到液晶大屏的演进,最新车型采用3D UI和智能驾辅技术,打造沉浸式智能体验。本文详述了3D UI人机交互设计中的车模数据和光影效果优化方法,强调多边形模型在流畅运行和光影效果方面的关键作用。在车模数据量和光影效果优化中,需注意调整精度、贴图,平衡效果和效率。未来,随着车载系统算力提升,车辆有望实现更复杂的3D模型处理,为驾驶者和乘客带来更真实、沉浸的视觉体验。

基于Polygon的雕塑法计算机辅助造型设计方法

计算机辅助设计技术已成为设计表现的必备手段,对于概念造型设计而言,接近传统手工方式的设计方法更易于被艺术设计师理解和接受。在对比目前主要计算机辅助造型方法的基础上,从分析传统手工雕塑造型的方式出发,针对概念设计和艺术造型设计的实际特征,提出了基于Polygon建模的雕塑法建模思路,给出了具体的建模步骤和合理布线的评价方法,并通过民间工艺品-泥塑马的造型实现过程进行了实例验证。实际运用证明,计算机雕塑建模方法对于艺术设计的三维软件建模理念具有较强的实用性,能够充分按照设计师的构思理念进行造型设计,对于创意设计而言更易于被造型设计师理解和运用。

一种实用的点/多面体分类算法

本文基于多面体表面的局部特性,提出了一种新的点/多面体分类算法,该算法适合于用边界表示法表示的任意多面体,可靠性高,具有很强的实用性。

新时代下三维动画专业基础课程设计的探索

目前许多高等院校都开设有三维动画专业,根据应用类型的不同涉及到如3DMax、Maya、Cinema4D等软件。同时,该专业的基础课程都会涉及到建模。三维模型的建模方式有很多种,从Polygon中的基本体扩展到平面图形的三维转换,从Nurbs中的编辑点挤出放样到二者之间的相互转换等。无论是哪一种方法,从布线结构的角度来看都遵守了一定的规律。笔者在多年任教过程中总结了一套关于三维动画基础课程的教学方法,通过具体分析一个模型的不同布线结构出发,来讨论什么样的布线才是最合适模型的。同时,通过分析当下游戏动画行业对模型制作的要求以及未来的发展趋势,衍生出笔者对如何教好三维动画专业课的一点思考。

基于地铁轨道交通环控系统的虚拟现实与仿真关键技术研究

本文以地铁轨道交通环控系统项目为例,对虚拟现实与仿真关键技术进行了开发流程论述:提出了符合虚拟现实与仿真项目的模型制作规范;分别介绍了3ds Max和Unfold3D软件制作UV的技巧;针对纹理贴图详细阐述了AO贴图与高真实感的PBR材质制作流程;最后论述了UGUI控件、Unity3D功能组件以及C#脚本语言在地铁轨道交通环控系统项目开发中的作用。本文的研究对于虚拟现实与仿真项目的开发具有较好的理论指导和实际操作借鉴意义。

实事求是选择三维建模方法探讨

随着计算机技术的飞速发展,三维动画也随之越来越广泛,制作速度就显得非常重要。本文就建模这一模块来阐述如何实事求是地选择建模方法来提高建模速度。

基于多媒体技术的3D建模方法与实践

3D建模就是利用三维制作软件通过虚拟三维空间构建出具有三维数据的模型。本文基于Maya软件研究了多媒体中多种3D建模,通过NURBS建模与多边形建模的实际模型的制作研究了3D建模的制作方法。

ON THE GROWTH OF ZERO ORDER LAPLACE-STIELTJES TRANSFORM CONVERGENT IN THE RIGHT HALF-PLANE

In this article, authors study the growth of Laplace-Stieltjes transform with zero order convergent in the right half-plane, define the exponential order and the exponential low order, and find the relations between them. Some results similar to Dirichlet series are obtained.

三维动画建模技术的应用研究探析

建模是三维动画设计制作的第一步,是三维世界的核心和基础,没有一个好的模型,其他什么好的效果都难以表现,3DMAX具有多种建模手段。除了内置的几何体模型和对图形的挤压、车削、放样建模以及复合物体等基础建模外,目前最流行的3D建模方法主要有多边形建模、非均匀有理B样条曲线建模(NURBS)、细分曲面技术建模。本文结合三维动画中物体的分类,具体探讨了当前三维动画中3D建模技术的应用研究。

Prediction and Control of Wrinkle and Fracture for Stamping Regular Polygonal Box

Based on the deformation characteristic of regular polygonal box stamped parts and the superfluous triangle material wrinkle model,the criterion of regular polygonal box stamped parts without wrinkle was deduced and used to predict and control the wrinkle limit.According to the fracture model,the criterion of regular polygonal box stamped parts without fracture was deduced and used to predict and control the fracture limit.Combining the criterion for stamping without wrinkle with that without fracture,the stamping criterion of regular polygonal box stamped parts was obtained to predict and control the stamping limit.Taken the stainless steel0Cr18Ni9(SUS304)sheet and the square box stamped part as examples,the limit diagram was given to predict and control the wrinkle,fracture and stamping limits.It is suitable for the deep drawing without flange,the deep drawing and stretching combined forming with flange and the rigid punch stretching of plane blank.The limit deep-drawing coefficient and the minimum deep-drawing coefficient can be determined,and the appropriate BHF(blank holder force)and the deep-drawing force can be chosen.These provide a reference for the technology planning,the die and mold design and the equipment determination,and a new criterion evaluating sheet stamping formability,which predicts and controls the stamping process,can be applied to the deep drawing under constant or variable BHF conditions.

Maya多边形角色建模技术初探

动漫产业发展迅速,其中三维动画占据了重要的地位。制作动画,建模是基础,为了让动漫形象和个性更加立体丰满,对角色模型的塑造就有了很高的要求。Maya Polygon建模,更适合有机物模型的创建。系统阐述多边形角色建模的原则和实用性技术,旨在使模型创建更加专业化。

Glass Forming Ability and Magnetic Property of Fe74Al4Sn2（PSiB）20 Amorphous Alloy

Based on the deformation characteristic of regular polygonal box stamped parts and the superfluous triangle material wrinkle model, the criterion of regular polygonal box stamped parts without wrinkle was deduced and used to predict and control the wrinkle limit. According to the fracture model, the criterion of regular polygonal box stamped parts without fracture was deduced and used to predict and control the fracture limit. Combining the criterion for stamping without wrinkle with that without fracture, the stamping criterion of regular polygonal box stamped parts was obtained to predict and control the stamping limit. Taken the stainless steel 0Cr18Ni9 (SUS304) sheet and the square box stamped part as examples, the limit diagram was given to predict and control the wrinkle, fracture and stamping limits. It is suitable for the deep drawing without flange, the deep drawing and stretching combined forming with flange and the rigid punch stretching of plane blank. The limit deep-drawing coefficient and the minimum deep-drawing coefficient can be determined, and the appropriate BHF (blank holder force) and the deep-drawing force can be chosen. These provide a reference for the technology planning, the die and mold design and the equipment determination, and a new criterion evaluating sheet stamping formability, which predicts and controls the stamping process, can be applied to the deep drawing under constant or variable BHF conditions.