查询词典 approximate limit

For a general parametric curve/surface, we usually cannot compute its exact implicit form. Even though its exact implicit form can be computed, the curve/surface implicitization involves relatively complicated computation and the degree is higher. Moreover, it may have unexpected components and self-intersections. All these unsatisfied properties limit the applications of the exact implicitization. So finding curve/surface approximate implicitization has become a practical problem. In this paper, we present an algorithm to solve the approximate implicitization of a given parametric curve by using a quadratic algebraic spline curve.

由于精确隐式化过程不一定可以实现，即使可以实现隐式曲线曲面的阶数高计算复杂，并且具有不希望的自交点和奇异分支，从而限制了隐式化的运用，所以寻求参数曲线曲面的近似隐式化问题成为很实际又重要的问题，提出利用二次代数样条曲线来实现一般平面参数曲线近似隐式化的一种算法。

In this paper, Galerkin method is employed. First, test functions to satisfy natural boundary conditions are selected. Then the approximate analytic formulations of the system frequency are derived. Meanwhile the approximate analytic formulation of the limit velocity is got.

采用直接法，首先选取满足自然边界条件的试函数，而后求出了系统固有频率的近似解析公式，同时也得到了极限流速的近似解析公式。

First, we use the time-descrete method for constructing an approximate solution, hence, establish a priori estimates of the approximate solution,we prove the existence subsequently by taking the limit of the approximate solution.

首先， 我们用时间离散化的办法构造逼近解，再对逼近解作必要的一致估计，然后通过对逼近解取极限，证明了弱解的存在性。

This paper presents the new bound theorems in structural limit analysis developed on the basis of the generalized variational principle. The approximate limit factors determined from the new bound theorems are closer to the exact limit factor than the ones obtained from the classical bound theorems.

本文给出在极限分析的一般变分原理[1]的基础上发展起来的极限乘子的新的上、下限定理[10]，由这个新的上、下限定理决定的极限乘子的上、下限比经典的上、下限定理给出的更为靠近准确解。

Firstly part of quadratic term of Taylor series is chosen; a low-dimension surface is used to approximate limit state surface ; and the modified reliability formula is derived.

首次选取泰勒级数的部分二次项，用一个距原点最近点处拟合的超低维曲面近似极限状态面。

During isothermal extruding of blank, in order to make the material fill successfully into the mold cavity and demould successfully, by using dressing on curved surface of the globoid cams and adopting circular arc transition on each connection, the blank with high precision and shape approximate limit was obtained.

在毛坯等温挤压过程中，为使材料顺利地充满凹模型腔以及成形后脱模顺利，通过在弧面凸轮曲面上加盖敷料及在各连接处采取圆弧过渡，以制得高精度的近似净形零件毛坯件；并采用MSC。

The relationship between transient response and shape design variables is highly non-linear, and the behavior of feasible domains is often not good, which may cause convergence difficulties. In order to improve convergence speed of iteration process, some algorithms the feasible domains adjusting, the adaptive move limit, the approximate line search and the approximate reanalysis, are adopted.

采用基于Newmark积分的直接求导法计算瞬态响应灵敏度，在序列二次规划算法中采用了可行域调整、近似—维搜索、自适应运动极限等改进技术，提高求解效率和收敛稳定性，以解决结构动态响应与设计变量的关系复杂、高度非线性，优化可行区域的性态不良等问题。

By virtue of method of continuum approximate limit, we obtained the solitons of the vibration of lattice in one-dimensional harmonic and inharmonic chains of polarized molecule, under the conditions considering and inconsidering the interaction of exciton with phonon, through solving moving equations of exciton and phonon.

运用连续极限近似方法，通过求解声子和激子的运动方程，得到了在不考虑激子与声子的相互作用和考虑激子与声子相互作用两种情况下的极性分子简谐链和非简谐链中晶格振动的孤子解，并得出了激子与声子的相互作用的非线性效应类似于晶格三次势的非线性效应，以及相同的非线性效应不论是同时作用还是单独作用都具有相同的非线性效应的结论。

Algorithm for determining the lower limit of the iterated times in IFSP;2. Stratigraphical division and lower limit of the Quaternary in Hunan;3. At present, the approximate solution of Voigt and Reuss's upper limit or lower limit and the calculating formula of Hashin and Shtrikman's upper limit or lower limit are accurate.

计算复合材料有效弹性模量上、下限的方法中，Voigt和Reuss的上、下限近似解及Hashin和Shtrikman的上、下限计算公式较为精确，但Voigt-Reuss近似解通常忽略了各向异性非均匀体的研究，是一个不全面的结果。

Furthermore, we will discuss the corresponding decay rates problem when the viscous term tends to zero.The first part is about the local existence. We will regularize the equations by the standard mollifier to get the approximate solutions . Then by making uniform estimates to the approximate solutions and by passing to the limit, we obtain the local existence for the above problem.

我们主要研究了此方程组古典解的局部存在性，爆破准则以及通过粘性消失方法来研究如上方程组的局部存在性和收敛率问题，主要结论有：(1)解的局部存在性利用光滑子对方程组进行正则化，从而得到原方程组的逼近解。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。