特征参数
- 与 特征参数 相关的网络例句 [注:此内容来源于网络,仅供参考]
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This paper presents an IFMC CAD model that consits of a geometry model and a material model, in which the geometry space acts as a base space and the material space acts as a bundle space. In this CAD model, the geometry model is based on the non-manifold model. In addition, a half-face data sturucture, which is derived from the half-edge data structure with the non-manifold feature of IFMC taken into account, is adopted to represent the geometry and topology information of the component. For the material model of IFMC, this paper focuses on the FGM component representation firstly and present a simplex-subdivision based CAD data exchange format, in which the material information is represented as a (n-1) simplex and material distributing feature is represented by the interpolation on the simplex-subdivision. Based on those, a part-building orientation optimization algorithm and an adaptive slicing algorithm for FGM component are presented in the paper. For the IFMC material model, the IFMC material information representation is divided into a meso-scale and a macro-scale representation. In the meso-scale, a concept named parameterized periodic functional meso-structure is presented as a unique form to represent the FGM (the homogeneous materials are regarded as a special FGM), the composite and the functional meso-structure material. The model of PMS is a three-tuple that contains the space state informatation, the material parameter and the material meso-scale distribution feature. The macro-scale material information representation is similar to the FGM components by interpolation of the control parameter of the periodical functional meso-structure based on the simplex-subdivision. Through an example of manufacturing-oriented IFMC CAD data processing, it is proved that the IFMC CAD model and the material information representation and process method proposed in this paper can provide a reliable data support for IFMC digital concurrent design and manufacturing.
本文将理想材料零件CAD模型建立在以几何空间为底空间、以材料空间为丛空间的结构上,使用非流形几何模型作为理想材料零件几何拓扑模型的基础,并在半边数据结构基础上,针对理想材料零件的非流形特征局限内部边界上的特点,给出了一个半面数据结构来表述零件的几何拓扑信息;对于理想材料零件的材料模型,本文先从功能梯度材料零件的信息表述与CAD数据交换和处理入手,将材料信息表述为(n-1)维单纯形,然后通过对三维几何区域的单纯剖分,以插值的方式表述零件材料分布特征;在此基础上,根据功能梯度材料零件分层制造中对CAD数据处理的要求,给出了综合考虑零件几何特征与材料特征的生长方向优化算法和自适应切片算法;而对于文中所定义的理想材料零件,本文将其材料信息表述分解到细观和宏观两个尺度进行,首先给出了细观尺度上参数化的周期性功能细结构概念,以此来统一表述功能梯度材料(单质材料作为特殊的功能梯度材料看待)、复合材料和功能细结构材料;把周期性功能细结构模型化为一个包含空间状态信息、材料构成参数和材料细观分布特征参数的三元组,以表达零件的细观材料特征;对于零件宏观的材料变化特征,则同样在几何区域单纯剖分的基础上,通过对细观尺度上周期性功能细结构控制参数的插值来完成;通过理想材料零件CAD数据处理的算例,验证了本文中理想材料零件CAD模型及材料信息表述与处理方法完全可以为理想材料零件的数字化制造提供可靠的数据支持。
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This paper presents an IFMC CAD model that consits of a geometry model and a material model, in which the geometry space acts as a base space and the material space acts as a bundle space. In this CAD model, the geometry model is based on the non-manifold model. In addition, a half-face data sturucture, which is derived from the half-edge data structure with the non-manifold feature of IFMC taken into account, is adopted to represent the geometry and topology information of the component.For the material model of IFMC, this paper focuses on the FGM component representation firstly and present a simplex-subdivision based CAD data exchange format, in which the material information is represented as a (n-1) simplex and material .distributing feature is represented by the interpolation on the simplex-subdivision. Based on those, a part-building orientation optimization algorithm and an adaptive slicing algorithm for FGM component are presented in the paper.For the IFMC material model, the IFMC material information representation is divided into a meso-scale and a macro-scale representation. In the meso-scale, a concept named parameterized periodic functional meso-structure is presented as a unique form to represent the FGM (the homogeneous materials are regarded as a special FGM), the composite and the functional meso-structure material. The model of PMS is a three-tuple that contains the space stateinformatation, the material parameter and the material meso-scale distribution feature. The macro-scale material information representation is similar to the FGM components by interpolation of the control parameter of the periodical functional meso-structure based on the simplex-subdivision.Through an example of manufacturing-oriented IFMC CAD data processing, it is proved that the IFMC CAD model and the material information representation and process method proposed in this paper can provide a reliable data support for IFMC digital concurrent design and manufacturing.
本文将理想材料零件CAD模型建立在以几何空间为底空间、以材料空间为丛空间的结构上,使用非流形几何模型作为理想材料零件几何拓扑模型的基础,并在半边数据结构基础上,针对理想材料零件的非流形特征局限内部边界上的特点,给出了一个半面数据结构来表述零件的几何拓扑信息;对于理想材料零件的材料模型,本文先从功能梯度材料零件的信息表述与CAD数据交换和处理入手,将材料信息表述为(n-1)维单纯形,然后通过对三维几何区域的单纯剖分,以插值的方式表述零件材料分布特征;在此基础上,根据功能梯度材料零件分层制造中对CAD数据处理的要求,给出了综合考虑零件几何特征与材料特征的生长方向优化算法和自适应切片算法;而对于文中所定义的理想材料零件,本文将其材料信息表述分解到细观和宏观两个尺度进行,首先给出了细观尺度上参数化的周期性功能细结构概念,以此来统一表述功能梯度材料(单质材料作为特殊的功能梯度材料看待)、复合材料和功能细结构材料;把周期性功能细结构模型化为一个包含空间状态信息、材料构成参数和材料细观分布特征参数的三元组,以表达零件的细观材料特征;对于零件宏观的材料变化特征,则同样在几何区域单纯剖分的基础上,通过对细观尺度上周期性功能细结构控制参数的插值来完成;通过理想材料零件CAD数据处理的算例,验证了本文中理想材料零件CAD模型及材料信息表述与处理方法完全可以为理想材料零件的数字化制造提供可靠的数据支持。
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According to the geology and well test data of Neopaleozoic tight reservoir in Tabamiao region, we begin with the conventional log response characteristic analysis and extract the classification ratio parameters to visual identify and evaluate reservoir characteristic. That is the lithologic, electric and physical ratio parameters and gas synthetical characteristic exponent.
依据塔巴庙区块上古生界致密储层各种地质、试井成果等的资料,从常规测井响应特征分析入手,提取建立了一套直观识别评价储层特征的分类比值参数,即"四性"测井特征参数:岩性比值参数、电性比值参数、物性比值参数和含气综合特征指数。
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The methods of computing for similar coefficient were Discriminance of Minimal Difference of Parameters, Discriminance of Limen of Tree Compositive Character and Synthetic Weight Similarity of Parameters. The contribution of all parameters were considering as same for DMDP and DLTC, but it estimate s the similarity between parameters according to the limen for DLTC. DMDP was based on the principal component analysis for wood transverse section micrograph characters and computing the similar coefficient according to the contribution of every parameter.
其中最小差值差数判别法与树种综合特征阈值法是将每个特征参数对木材横切面显微图像特征的贡献率视为一致,只是树种综合特征阈值法是以阈值的大小来判断特征的相似性,而综合加权相似法是建立在对木材横切面显微图像特征参数的主成分分析的基础上,根据每个特征参数的贡献率大小计算相似系数。
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First, the algrithm classify the measurement characteristics as point, line and surface which can be classified to conicoid and free surface. Then, this algorithm establishes the parametric equation according to various features. After that this paper brings forward the characteristic parameters utilising least square method with several characteristic points. Finally high precision probe radius compensation is carried out according to the features.
该算法首先把测量特征分为点、线、面3种基本特征(其中面特征又分为二次曲面和自由曲面),然后建立各种特征的参数方程,利用测量得到的少量特征点,采用最小二乘法拟合得到被测特征的参数,最后根据被测特征参数进行高精度半径补偿。
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First it concludes elementary methods for product modeling such as feature recognition, feature-based design and feature mapping. Then it probes into the mechanism of constraint-based feature parametric modeling, representation of feature parametric model and methods for solving constraint in details. At the end it proposes a feature-based modeling system that makes good use of resources and synthesizes many feature modeling methods, and analyses the development of prototype system oriented to actual application.
首先全面归纳了基本的基于特征的产品建模方法,包括特征识别、基于特征设计和特征映射方法,然后对基于约束的特征参数化建模、特征参数化模型的表达和定义方法以及约束求解方法进行了深入研究,最后提出了一个充分利用现有资源,特征识别、基于特征设计和特征映射共用的特征建模系统,并探讨了面向实际应用的原型系统的开发技术。
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Space curve is one of the basic elements in geometric modeling, and its effective representation is the basis of modeling. Parametric representation based on features is a kind of high-level representation including semantic information. In Chapter 4, para- metric representations based on features for free form space curve are investigated, and a parametric model for the loop of plain knitted fabric is established, in which 5 parameters with practical meanings are used to represent the shape of a loop and the relationship between loops. A new shrinkage prediction method for knitted fabric are proposed based on the parametric representation and energy minimizing. Experimental results on some plain knitted fabrics illustrate the feasibility of the proposed method.
空间曲线是造型中最基本的几何元素之一,对其有效的表示是造型的基础,而特征参数化表示是其中一种包含语义信息的高层次表示,本文对空间自由曲线的特征参数化表示进行研究,建立了一种针织物线圈的特征参数化几何模型,采用5个具有实际意义的参数表示织物线圈的几何形状及线圈之间的位置关系,并将该模型与能量极小化的方法相结合,得到了一种能较好地预测针织物缩水率的新模型,对随机选取的一些针织布缩水预测实验表明了算法的可行性。
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In this chapter, three kinds of target recognition methods are performed, which are:①Target recognition method based on the description of polarization parameter plane. The echo polarization states of target are projected onto the polarization state plane described by the ellipticity ε and the tilt angle τ of the polarization ellipse, the change of parameter following ferquency becomes the chart. According to the changing trait of the chart, the multidimensional polarization feature space of target has been contructed. Furthermore, a series of polarization feature parameters used in designing the structure of target recognition device are extracted, and they are insensible to the posture of target.②Target recognition method based on the description of Poincare polarization sphere. The echo polarization states of target expressed by Stokes vector are projected onto the Poincare polarization sphere. The conception of polarization ferquency stability, which is used in describing the dynamic distribution characteristics of the target echo polarization states on Poincare polarization sphere, has been defined. A group of polarization feature parameters used in designing the structure of target recognition device are extracted, and they are insensible to the posture of target.③Target recognition method based on the description of frequency sensitivity. In accordance with the conception of the polarization state distance defined on Poincare polarization sphere, the frequency sensibility of the physical structure property of target has been investigated, the frequency distribution feature curves in PSD domain are obtained, and targets'features are extracted by means of the curve-fitting method with Least Square Criterion.
这章具体研究了基于三种极化散射特性描述的相应的目标识别方法:①基于极化参数平面描述的目标识别方法,将目标回波极化状态投影到以极化椭圆参数,即椭圆率角ε和倾角τ表征的极化状态平面上,参数随观测频率的变化就形成了图,根据图的变化特点构造了目标的多维极化特征空间,并提取了不敏感目标姿态变化的极化特征参数组来设计目标的识别器结构;②基于Poincare极化球面描述的目标识别方法,采用Stokes矢量表征目标回波的极化状态,并将其投影到描述极化状态的Poincare极化球面上,定义了极化频率稳定度的概念用以刻画目标回波极化状态在Poincare极化球面上的动态分布信息,提取了准方位不变性的目标极化特征,最后设计了目标的识别器结构;③基于频率敏感性描述的目标识别方法,通过在Poincare极化球面上所定义的极化状态距离的概念,研究的是复杂目标物理结构特性对探测信号频率的敏感程度问题,获得了在极化状态距离下的频率分布特性曲线,采用最小二乘估计曲线拟合方法,它既用于极化特征的降维,同时又直接将拟合参数作为目标的分类特征。
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In this paper, the sorting of wear, the mechanics of wear particle formed and the characteristics of wear particles are introduced, and morphology characteristics parameter of wear particle are determined, which is particle brim digital feature. Based on image characters, after pre-process, section and extracting of contour parameter of wear particle using image process technique, four shape character parameters are extracted by fourier series expansion. After analyzing fundamental principle and shortcomings of neural network, current BP algorithm is improved in output optimization, network linearization implication optimization and adding momentum, and then astringe speed of BP algorithm.
本文介绍了磨损的分类以及磨粒的生成机理、磨粒的形态特征,应用摩擦学系统分析的观点,确定磨粒边缘数字特征为磨粒的识别特征参数;根据磨粒图像的特征,利用计算机图像处理技术对磨粒图像进行预处理、分割、轮廓参数的提取,采用傅立叶级数展开式提取磨粒四个形状特征参数:圆形度、散射度、凹度、细长度;针对 BP(Back-Propagation)神经网络收敛速度慢的特点,对现行的 BP 算法进行改进,并通过实验验证改进后的网络收敛速度快;研究设计了磨粒图像采集系统;利用 BP 算法建立磨损磨粒自动识别算法模型 AWPRM(Auto Wear Particle Recognition Model)。
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According to the geology and well test data of Neopaleozoic tight reservoir in Tabamiao region, we begin with the conventional log response characteristic analysis and extract the classification ratio parameters to visual identify and evaluate reservoir characteristic. That is the lithologic, electric and physical ratio parameters and gas synthetical characteristic exponent.
依据塔巴庙区块上古生界致密储层各种地质、试井成果等的资料,从常规测井响应特征分析入手,提取建立了一套直观识别评价储层特征的分类比值参数,即&四性&测井特征参数:岩性比值参数、电性比值参数、物性比值参数和含气综合特征指数。
- 推荐网络例句
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By the time of its fall, most of the prisoners were writers who had written against the corruptions of the government.
到它被攻陷的时候,里面多数的犯人是写了反对政府贪污文章的作家。
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The most obvious variation to ovum morphological character was that the color was changed from light green to sepiaceous in embryonic development, and all the ovums were almost hatched after 96h.
在胚胎发育过程中卵的形态特征最明显的变化是颜色从淡绿到深褐色,卵在发育96h后卵基本全部孵化。
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There was a conflict between plebs and patricians in ancient Rome in 494BC.
在公元前494年,罗马发生了一次平民反对贵族的斗争。