查询词典 iterative computation

3D-CTM (Coupled Thermo-Mechanical Forming Simulation) software for precision forging process of aero-engine blade was developed. The key technologies of 3D coupled rigid-viscoplastic thermo-mechanical FEM simulation of blade forging process were studied systematically. By using the remeshing method of contracting from the boundary to the inner, new mesh system from old distorted mesh system can be obtained. A method of modifying the position of nodes touching on the die according to its original normal was proposed to avoid "dead lock" problem due to uncontinuity of normal of scatted die meshes. The pseudo-static iterative algorithm was used to simplify the coupled thermo-mechanical computation. In particular, formulations to determine relaxation factor β was established for rigid viscoplastic FEM adopting penalty function method, and an improved cubic factor rapid algorithm derived from these formulations was proposed by combining with the advantage of advance and retreat search method.

采用基于边界构形的内缩法，实现了三维畸变网格的重新划分；提出了初矢修正法对触模节点的位置进行修正，解决了由于离散的模具网格的法矢不连续造成的&死锁&问题；采用准静态迭代法简化了速度场和温度场耦合计算过程；特别是针对减速因子β的选取，建立了适用于三维复杂成形过程刚粘塑性罚函数法有限元三次因子法的计算公式，并结合进退搜索法提出了改进的三次因子快速算法，提高了模拟计算效率和稳定性，在此基础之上，开发了面向叶片精锻过程的三维刚粘塑性热力耦合有限元模拟分析系统(3D-CTM)，系统的可靠性得到了圆柱体镦粗的验证。

To extend the SIC technique to turbo-coded systems, an iterative IC with ordered SIC at front-end is proposed. To avoid unnecessary computation, the ordering information obtained from SIC front-end is utilized in a low-complexity stopping criterion with high efficiency. In addition to bit-wise interference cancellation, the SIC technique is also applied to code-block-wise interference cancellation. And, only the bits in incorrect blocks should be preceded to the next outer iteration. As a result, huge amount of computational complexity can be saved, and better performance is achieved.

最后，我们延伸序列式干扰消除的概念至有通道编码的系统，与涡轮码解码同时考虑，首先根据排序资讯，提出一提早停止（early-stopping）准则以减少涡轮码解码时不必要的运算，与其他提早停止准则比较，在几乎相同的检测能力下，此准则具有快速及低计算复杂度的特性，接著提出一包含前述准则之递回式干扰消除法，将序列式干扰消除运用在符码及跨级之码块干扰上，并且只有被检定为错误的编码区块讯号需要再进一级的递回检测，此法不仅在效能表现上更为优越，也节省了大量且不必要的计算量。

This model based on Brews's charge sheet model and the above non-iterative computation of surface potential also accounts for DIBL effect, kink effect, and channel-length modulation.

基于Brews的薄层电荷模型和上述非迭代计算表面势，本电流模型同时考虑了漏致势垒降低效应、kink效应和沟道长度调制效应。

In order to reduce the computation complexity of the matrix-vector product and the iterative times in the process of matrix inversing, a new wavelet-like preconditioning operator based on the lifting scheme is used.

一种新的基于提升法的类小波变换预处理算子的使用，降低了矩阵向量积的计算复杂度和求逆过程中的迭代次数。

The quasi-3D S〓/S〓 streamfilaments iterative computation is used to analyse the flow field in centrifugal impellers compressing perfect gas and real gas respectively.

使用准三元S2/S1流面迭代计算，对压缩理想气体和实际气体的离心叶轮流场作了分析。

Different from previously presented threshold RSA signature schemes, this new scheme can effectively avoid computation of any element\'s inverse in any algebraic structure such as Z_(φ and Z_N, which makes the complicated algebraic extension, parameter constraint and inversion pre-computation all unnecessary.

该体制基于整数矩阵运算，不需要对任何非域代数结构中的元素求逆，为构造高效实用的门限RSA签名方案奠定了基础。

This thesis contributed to the comprehensive study of the Finite-Difference Time-Domain method and its application to the numerical computation of radiated electromagnetic fields in switched mode power supplies. The work includes mainly three parts: the study on the performance of PML absorbing boundary condition applied to pseudo low frequency electromagnetic problems; the validation of the FDTD method with PML absorbing boundary conditions and the corresponding computer software based on the numerical study of the electromagnetic field of an electric dipole antenna, and its application to the numerical computation of radiated electromagnetic fields in switched mode power supplies; the development of an improved alternating direction implicit finite-difference time-domain method.

在综合前人工作基础上，本文对时域有限差分法及其在开关电源辐射电磁场数值计算中的应用进行了系统的分析和研究，其核心内容包括：伪低频电磁场数值计算中PML吸收边界条件性能的研究；基于基准问题—电偶极子天线三维辐射电磁场，验证了本文构造的基于PML吸收边界条件的三维FDTD法及其计算软件，并应用于高频开关电源辐射电磁场的数值分析；提出了一种改进的交替方向隐格式时域有限差分法。

In computation, or at least in our old models of computation, an arbitrarily small event can and often does cause an arbitrarily large effect.

在电脑计算中，或至少在我们的日常模式的电脑计算中，一个任意小的事件往往能够造成任意大的效果。

The foundation of this system provides a good reference to promote the standardization and intelligence of the overhaul and maintenance of vacuum switches. This paper develops a special HF pulse power supply for internal pressure estimation, which achieves the output of HF-HV sinusoidal pulse wave whose frequency and amplitude can be modified respectively, and meets the design requirements according to the results of Simulink simulation and practical experiments. With the help of AT89S52, this paper designs an I~2C serial bus based signal detection system for peak value signal acquisition of HF pulse currents, which communicates with the upper computer by asynchronous serial communication for uploading the data. In the upper computer, a human computer interface is developed by Matlab software, whose functions are to do some computation and graphic display, such as calibrating the relation curve of vacuum degree and peak value of HF pulse currents, vacuum degree computation, and vacuum lifetime evaluation analysis basing on grey forecasting model as well as making relative suggestions.

本文研制了用于真空度检测的高频脉冲电源，通过Simulink仿真和试验检验其满足设计要求，实现了电压幅值和频率独立可调的正弦波高频高压脉冲输出；利用以AT89S52为核心基于I~2C串行总线的信号检测系统实现高频脉冲电流峰值信号的采集，通过异步串行通信实现单片机与计算机之间的数据通信，将检测数据传至上位机；在上位机利用Matlab开发人机交互界面，实现相关数据处理和图形显示，包括真空度——高频脉冲电流峰值关系曲线标定、真空度数值计算、基于灰色预测模型的真空寿命评估分析和提出相应决策建议。

The control volume integration was applied to deduce the discrete expressions of the convection-diffusion equations. The staggered grid and SIMPLE algorithm were introduced to deal with coupling between pressure and velocity, and then the numerical computation expressions of such variables as fluid flow velocity and pressure were deduced. Using the backward difference method and incremental theory to discretize the governing equations for fields of chemical reaction, material structure and chemorheology, the numerical computation expressions of variables such as the monomer conversion, average molecular weight and fluid viscosity were constructed.

应用控制容积积分法导出了对流—扩散方程的离散表达式，引入交错网格技术与SIMPLE算法，实现了耦合的压力场与速度场的分离式求解，推导得到了流体的流动速度、压力等物理量的数值计算式；采用向后差分方法和增量方法，实现了化学反应场、材料结构场、化学流变场控制方程的离散，获得了反应转化率、聚合物平均相对分子质量、流体黏度等物理量的数值计算式。

Nowadays, most of research are to build a transmutative Petri Nets through adding controlling place sets, controlling arc sets and controlling policy to the basic Petri Nets, while the Controlled Petri Nets could be used to argue many controlling theory problems conveniently and to induce many logically and physically supervisory and solve the Event Feedback Controlling Problems and State Feedback Controlling Problem in DEDS supervisory theory.

目前大多数的研究表现为在变形后的受控Petri网基础上，利用各种方法求得各种逻辑型、结构型控制器，解决DEDS监控理论中的事件反馈控制问题与状态反馈控制问题。

On one hand, there are discussions with the works council and union about extension of short time working up to the end of September.

一方面，有讨论，工程理事会和联盟关于延长工作时间短至9月底。