有向曲面 的英文怎麼說
中文拼音 [yǒuxiàngqūmiàn]
有向曲面
英文
oriented surface-
Mount sainte - genevieve formed an enormous mound to the south ; and it was a sight to see from the summit of notre - dame how that throng of narrow and tortuous streets ( to - day the latin quarter ), those bunches of houses which, spread out in every direction from the top of this eminence, precipitated themselves in disorder, and almost perpendicularly down its flanks, nearly to the water ' s edge, having the air, some of falling, others of clambering up again, and all of holding to one another
聖日芮維埃芙山像一個巨大圓瓶兀自隆起在東南邊,這倒是很值得從聖母院頂上觀看一下的:只見那許許多多狹窄彎曲的街道(今天的拉丁區) ,那密密麻麻的屋宇,從山頂上向四面八方撒散開來,幾乎一溜筆直地沿著山坡俯沖下去,直至河邊,有的像要跌倒,有的像要再爬起來,但又都似乎彼此相互扶持。Therefore, these canines must stand far apart and be of good length so that the front surface of the muzzle is broad and squarish and, when viewed from the side, shows moderate layback
所以下犬齒必須有足夠的長度,而且彼此間有足夠的距離,以形成口吻前部的曲面,從側面觀察顯得有點方、有點寬、還有點向後。The re technique is generally composed of 3 - d surface digitalization, data procession, surface reconstruction, cad 3 - d modeling and rapid manufacture, etc. the reverse engineering cad / cam system has broad industrial usage, and the research work has extremely theoretic and application importance
Re技術通常涉及三維測量(表面數字化) 、數據處理、曲面重構、三維建模及快速製造等相關技術。逆向工程cad cam系統具有廣泛的工業用途,其研究開發工作具有較大的理論意義和應用價值。In the thesis. reading the iges file - 3 - and all the geometry entities and annotation entities are extracted ; on the base of geometry entities extracted, geometry entities are classified based to their three views. a new data structure is proposed to describle 3d form features ; inspection items of the workpiece are recognized ; the cmm - based inspection planning system is built ; on the other hand, as a part of cims, cmm need exchanging data with the software of cad / cam, so iges export interface is developed based on iges standard. in order to show the whole information of the surface, the 3 - dimensional free - form surface is drawing using the opengl
通過讀取iges文件對實體進行分離、提取、識別出對工件進行描述的原始信息;在此基礎上,西安理工大學碩士學位論文提出一種優化演算法對三視圖自動進行分離,建立了一種對工件進行三維描述的數學模型,照此模型對工件進行立體重構;識別出工件的各種檢測信息,提出一種對公差信息進行描述的數學模型,井與三維立體相結合,生成有檢測意義的三維實體;根據三坐標機的測量系統,生成相應的檢測規劃;另一方面,作為cmis的一部分,應具有與cad cam軟體之間的數據交換功能,本文還開發了iges輸出介面,採用opengl繪制三維空間曲面,向用戶展示其全面信息。In the framework, a control mesh may be arbitrary one - dimensional or two - dimensional orientated topological manifold, and the curve or surface is defined on differential manifold homeomorphic to the control mesh with a potential function as its basis functions. this method is an extension of nurbs, which efficiently overcomes the limitations of nurbs
廣義有理參數曲線曲面定義在與控制網格拓撲同胚的微分流形上,以高度一般的勢函數為基函數,其控制網格可以是任意的一維拓撲流形和二維可定向拓撲流形。Based on the review, the fluid flow and heat transfer in the curved circular and rectangular pipes have been researched by employing perturbation method and numerical simulation with a physical model under the rotational orthogonal curvilinear coordinate in a rotating curvilinear pipe with multi - parameters. we firstly analyzed the fully developed fluid flow and heat transfer, mixed convection heat transfer, the development of flow and heat transfer in the inlet in different cross section ( circular, elliptical, annular and rectangular crossection ). the variations of the secondary flow, axial velocity, distribution of temperature, the friction force on the wall, the ratio of friction factor as well as the nusselt number with different dimensionless parameters had been examined in detailed
本文在總結和分析了一個世紀以來有關曲線管道流動和換熱特性的研究成果的基礎上,以旋轉正交曲線坐標系統下的多參數旋轉螺旋管道中的對流傳熱為物理模型,通過攝動方法和有限體積法,首次對各種截面(圓截面、橢圓截面、環形截面、矩形截面)旋轉曲線管道內充分發展流動的流動結構和傳熱特性(包括耦合對流傳熱特性)以及旋轉曲線管道開口段發展流動的流動結構和換熱特性進行了系統的數值模擬和理論分析,詳細討論了各種無量綱參數對管道內軸向速度分佈、二次流結構、溫度分佈、壁面摩擦力、摩擦系數比以及管道nusselt數的影響,獲得了若干創新性成果。In this dissertation, for the need of engineering, berchand surface is put forward and studied which is refined and enhanced from the common characteristics of gyration surfaces, developed surfaces and normal circular - arc helical surfaces. according to which, many kinds of important surfaces can be structured
論文從工程需要出發,提出並研究了白川德曲面,這是對回轉面、可展面、法向圓弧螺旋面共性特徵的提煉與升華,據此可以構造和發展出各種有重要應用價值的曲面。This paper discusses the formation algorithm of a terrane with folds. to form a fold with less lean, triangulation from scattered points in space and surface reconstruction are used. to form a fold that has superposition along z - axis, the single - value surfaces that compose the fold should be constructed separately and assembled later
研究了帶有褶曲的巖層面的構造方法,對于傾角不大的褶曲用先進行空間三角剖分,然後重建曲面的方法構造;對于在z方向上有重疊的褶曲先構造出各單值曲面然後組合起來得到。In the case of closed surface, we obtain the following result : theorem 3. 1 let m be a closed surface with parallel mean curvature direction in r4 ( ), which admitting an isometric deformation preserving mean curvature
在閉的情況下,我們得到如下結果:定理3 . 1設m是r4 (約中平均曲率方向平行、非臍的閉曲面.若m容有保持平均曲率方向平行、且保平均曲率的等距變形曲面應,則m有常平均曲率Two methods are given. one is obtained by using degree reduction of interval rational bezier curves in two parameter directions according to the character of tensor product, which is called " single step method ". by comparison for degree reductions produced by the different order in two parameter directions, the relationships of the approximation results are discussed
然後討論了矩形域上區間有理bezier曲面的降階問題,給出兩種降階演算法:一個是針對張量積的特點將問題轉變為兩參數方向的區間有理曲線的降階逼近,即「單步法」 ,並討論單步法沿兩參數方向不同次序降階的關系。Nurbs surfaces with single interior knots are simple and used widely. the thesis main aims at biuquartic, biquintic, k x fc - degree b - spline surfaces and bicubic nurbs with single interior knots. one of the contributions is to apply knot refinement and the geometric continuous conditions of bezier surfaces to deduce the geometric continuous constraints of nurbs patches and obtain the intrinsic equations of common boundary curves, where the intrinsic equations are the special phenomena of nurbs surfaces
節點向量是內部單節點的nurbs曲面是最簡單也是最常用的,本文重點針對單節點的雙四次、雙五次和雙k次b樣條曲面及雙三次nurbs曲面,運用節點插入技術和b zier曲面的幾何連續理論成果,導出了它們之間的幾何光滑拼接條件,同時得到了公共邊界曲線所必須滿足的本徵方程,其中本徵方程是nurbs曲面所獨有的現象。The author ' s work gives new way, which is beneficial to real time interaction and can efficiently reduce computing time as well as data storage amount. these algorithms can find good use in numerical machining, robotics, form - position tolerance and computer graphics. ( 3 ) degree reduction for nurbs curves and surfaces by applying the theory of the best uniform approximation of chebyshev polynomials and the explicit matrix representation of nurbs curves, this thesis centers on the research of the explicit nearly best approximation of multi - degree reduction of nurbs curves
以上關于等距曲線的幾何逼近與代數逼近的演算法改革了當前國際圖形界只能對基曲線沿法矢方向平移定距離的點作近似逼近的固定模式,創造了利於交互操作,能有效地減少計算量及數據存儲量的新方法,可在數控加工、浙江大學碩士學位論文機器人、形位公差學、計算機圖形學中獲得很好的應用( 3 ) nurbs曲線曲面降階應用nurbs曲線的顯式矩陣表示及chebyshev多項式逼近理論,以實現nurbs曲線顯式一次性降多階的近似最佳逼近為目標進行了研究Chapter 1 ( the introduction ) gives a review of the development situation in virtual deformation design and surface reconstruction research and application. in this background, the significance and contents of mesh modeling, mesh optimization and mesh surface reconstruction in virtual environment are proposed particularly
曲面重建技術在cad工程與可視化領域有著廣泛的應用,本文基於pro e系統三維造型信息,提取三角剖分網格,面向曲面變形研究網格模型建模、網格模型優化及幾何重建技術。The longitudinal stresses in the tunnel structure calculated by using the model of tamura & okamoto are obviously greater than the stresses in transverse direction obtained by using two dimensional finite element analysis. it is proposed that the axial and bending stresses should not be ignored for the underground structural design
計算結果表明,由彈簧質量模型算得的地下結構在地震作用下縱向振動和橫向振動產生的縱向和彎曲正應力及剪應力明顯高於由二維平面有限元算得的橫向平面內產生的正應力和剪應力,由此可見軸向應力和彎曲應力是地下結構抗震設計中不容忽視的因素。Basing on nurcc scheme we can construct surfaces that can interpolate nurbs curves and have different local continuous order. our method enables subdivision surfaces to be used in the field of complex shape design of industry products
利用非均勻的catmull一clark細分方法,我們可以構造能夠插值若干條nurbs曲線、且具有不同的局部連續階的細分曲面,使得細分曲面走向各種復雜工業產品造型設計的應用領域成為可能In the second part, we investigate the compact submanifolds m with the parallel isoperimetric section in the real space forms rm ( c ) and prove that if there exists a parallel isoperimetric section on m, and the sectional curvature of m is always greater than zero, then m is contained in a hyper - sphere ; and get that the gauss curvature of the compact surfaces m with constant mean curvature in constant curvature space r4 ( c ) is always greater than zero, then m is a totally geodesic surface or a sphere, where an isoperimetric on m means a unit normal vector field defined globally on m with m1 ( ) = constant
( 2 )研究了實空間形式r ~ m ( c )中具有平行等參截面的緊致子流形m ,證明了具有一平行等參截面的子流形m ,如果m的截面曲率恆正,則m包含在r ~ m ( c )的一個超球面內;對于常曲率空間及r ~ 4 ( c )中具有常平均曲率的緊致曲面m ,如果m的高斯曲率處處大於零,則m或為r ~ m ( c )中的全測地曲面或為一球面。這里m上的等參截面是m上整體定義的單位法向量場,使得m關於它的平均曲率m _ 1 ( )是常數。Its properties and design method is discussed in chapter 4. for control meshes with arbitrary topology, we present a universal method in chapter 5 to construct parametric curves and surfaces. generalized rational parametric surface can be controlled precisely and flexible, and it is easy to model local features and 3d primitives
然後,在第五章中,我們將控制網格進一步推廣到任意可定向二維拓撲流形,提出了一個通用的方法將控制網格映射到與之拓撲同胚的微分流形上,統一了廣義有理參數曲線曲面的構造過程。And the conclusion is that vita method is a more reasonable method in burst detection when the threshold value is between 0. 7 to 1. 0. in order to investigate the influence of transverse curvature of the wall, the direct numerical simulated data bank of turbulent channel flow is also analyzed. the mean velocity profile in pipe and channel flow is compared
本文還對圓管和槽道內的猝發事件進行了分析,得到的圓管和槽道內的猝發周期大致是相同的,但是在猝發的強度上槽道要大於圓管;並且進一步的分析表明猝發強度的差別主要在於徑向速度的差別,這說明壁面橫向曲率對于徑向的流動影響較大,而對流向流動幾乎沒有影響。Maximum genus of graphs is a characteristic parameter, which determines a graph whether has a 2 - cell embedding in a. certain orientable surface
圖的最大虧格是刻劃圖在某個定向曲面上是否有2 -胞腔嵌入的一個特徵參數。It gives a relationship between a surface integral over an oriented surface and a line integral along a simple closed curve
它建立了有向曲面上的曲面積分與它的邊界曲線積分的關系。分享友人