查询词典 discretization error

In order to overcome the limitation, by using the character of in size order for continuous attributes and error theory of statistics, this paper proposes an algorithm of discretization based on cluster.

文中针对这一缺陷，利用连续数值属性有序性的性质和统计方差理论，提出了一种基于聚类的连续属性离散化算法。

The coordinate transformation and numerical integration was executed on the discretized tetrahedral elements based on which the 3-D MT vector-finite element method was implemented. A whole computation framework for 3-D vector-finite element method with unstructured mesh was given. Based on this some typical models were tested which has demonstrated that our algorithm could distinctively avoid problems caused by the fake solution and both the accuracy and efficiency were enhanced which made our algorithm has a bright future for further application.3. According to theory of Sobolev vector space and the discretization of Helmholtz space, the error estimate which was suitable for 3-D MT vector-finite element modeling was deduced by which the procedure of adaptive technique was guaranteed.4. Based on the fully unstructured tetrahedralization and optical strategy, the 3-D magnetotelluric h-adaptive vector-finite element method was presented through combining the error estimate. With this work, the accuracy and creditableness for 3-D MT complicatedly modeling was guaranteed.5. The 3-D magnetotelluric h-adaptive vector-finite element algorithm with unstructured mesh was implemented.

针对非结构化的四面体单元，采用坐标变换和数值积分方法，实现了MT三维矢量有限单元分析，建立起基于非结构化网格的三维MT矢量有限元计算流程，并对典型模型和国际标准电磁模型进行了数值模拟，结果对比和分析表明，基于非结构化网格的三维MT矢量有限元不仅消除了节点型有限元的伪解，而且具有很高的计算精度和速度，有广阔的应用前景。3、根据Sobolev函数的向量空间和Hemlholtz空间的分解，推导出基于残差的三维大地电磁矢量有限元后验误差估计公式，为三维大地电磁自适应矢量有限元数值模拟的实现奠定了基础。4、在完全非结构化四面体单元剖分及优化基础上，结合三维大地电磁矢量有限元后验误差估计公式，提出了基于非结构化网格的三维大地电磁h-型自适应矢量有限元计算策略，保证了对复杂大地电磁模型数值计算的精度和可靠性。5、实现了基于非结构化网格的三维大地电磁h-型自适应矢量有限元计算流程，对典型模型和国际标准电磁模型进行了数值模拟。

The nonlinear sliding mode controller is taken as an example, the implementation form of δ operator discretization control, the error analysis and the algorithms stability are studied both theoty and engineering application.

数值仿真表明，当高速开关阀的节流孔流量系数、摩擦片的磨损量、摩擦系数、传动系的弹性系数等因素在允许范围内变化时，滑模控制器的跟踪误差远低于一般的PID控制器。

DSP is used to realize digital controllers of velocity-loop and position-loop. Analyze and validate that dividing high-level continue controller to several low-level controllers, then discretize the low-level controllers to form series controller can depress the discretization control error.

采用DSP实现速度环和位置环的数字控制器，分析并验证了连续域高阶控制器分解成连续域低阶控制器，将低阶控制器离散后进行串联控制，这种实现方式的数字控制器与连续域控制器之间的控制误差，将远小于直接将连续域高阶控制器离散成高阶数字控制器产生的控制误差。

We use the boundary integral method to simulate the spherically symmetric collapse of a cavitation bubble, a free-surface potential problem having analytical solution. Evolving error curves are given in the thesis, and the influences of various discretization methods on the accuracy and the stability are compared.

我们使用边界积分法模拟空化气泡的球对称溃灭，一个具有分析解的自由面势流问题，给出了计算误差的演化曲线，比较了各种数值离散法对精度和稳定性的影响。

The invention performs pseudo bit error rate statistic by utilizing the message of multi sampling points in each modulation symbol of discretization system, and again performs one-to-one mapping by utilizing corresponding relation between the pseudo bit error rate and the signal-to-noise ratio, thereby obtaining signal-to-noise ratio estimation value.

本发明利用了离散系统每个调制符号中多个采样点的信息进行伪误码率统计，再利用伪误码率与信噪比之间的对应关系进行一一映射，从而得到信噪比估计值。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。