查询词典 finite difference approximation

In the fifth part, we obtained a solution of the boundary function for the Laplace equation by knowing some of its interior points values of five-point difference approximation.

给出从Laplace方程的解的内点值求边界函数的方法。

The remnant nis the difference between the actual pilot output and the linear approximation to it.

剩余值n是驾驶员的真实输出和它的线性近似之差。

By using the Tadmor's convergence criteria for the difference approximation of the hyperbolic conservative e2 quation and introducing some adjusting parameter in the nonvanishing viscosity , some convergence properties are obtained.

Descripción ：摘要：应用Tadmor 的关于双曲型守恒方程式差分逼近的收敛性判别法，对于若干差分逼近式，引入一些参数，只要在上机时适当调整此参数值，即可得到其收敛性。

Based on the classical theory of electromagnetism, the relation and the difference between OAM and the parameter of the beam in paraxial approximation are analyzed.

从经典电磁场理论出发，主要介绍了傍轴近似条件下，光束的轨道角动量和光束的参数之间的关系。

Then, a correction item to remove the influence of WIEN's approximation on ALPHA difference spectrum was developed.

以此为基础，在不考虑大气下行辐射影响的条件下，借鉴ALPHA导出发射率法和ASTER TES算法的优点，提出一个新的发射率温度分离算法。

The wave equation of electric in the waveguide can be translated into a coupled difference equation of second order by centered differency approximation.

通过中心差分法可将电场满足的波动方程化为一组耦合二阶差分公式形式。

The paper investigates both block-type pilot linear minimum mean square error algorithm and IEEE802.16 OFDM channel estimation analysis. Simulation results confirm the block-type pilot structure is more suitable for IEEE802.16 system. An optimal pilot setting algorithm, based on space frequency domain, is explored and the pilot chart is presented. The proposed algorithm finds its application in MIMO-OFDM. Simulation results show the algorithm presents a good approximation to the perfect channel state information curve, with about 2dB difference in SNR. The simulation results also demonstrate the algorithm achieves fairly high stability in the environment of fast fading, performance of the proposed algorithm is better that of pilot training channel estimation.3. Taking into account the characteristics of IEEE802.16 OFDM system, OFDM system simulation platform is constructed in Matlab, exploiting simulink as a tool. OFDM modulation and demodulation simulation system are configured on LabVIEW platform. All the system signal processing is simulated, including defining system parameters, designing modulation model, and verifying all the proposed algorithms under different environments, such as white Gaussian noise, multi-path fading, with or without guard interval etc. Bit error performance is evaluated. The research provides valid theoretical basis for practical OFDM system performance evaluation.4. Taking advantage of software radio, the paper designs a hardware platform with both 256-IFFT/FFT and 512-IFFT/FFT OFDM schemes co-existing in one platform. You can predetermine one from the two schemes to carry out almost the same model function with different system performance and parameter setting.5. Referring to IEEE802.16 standard, the paper proposes a design method for generating signals and frames suitable for laboratory investigations implemented in laboratory environment.6. Based on 6701evm digital evaluation card, combined with analogy front-end, the paper designs a DSP software model to deal with baseband signal processing. An overall OFDM scheme, with modulation and demodulation function, is accomplished.

讨论分析了MIMO-OFDM中一种基于空频域的最优导频设置算法，给出了导频图案，通过仿真实验表明，该算法与理想的信道状态信息曲线非常接近，信噪比差距约在2dB左右，并且在快衰落条件下具有较好的稳定性，其性能要优于基于前导训练的信道估计方法。3、根据IEEE802.16OFDM系统特点，论文分别在Matlab中应用Simulink工具构建OFDM系统仿真平台、在LabVIEW平台上实现了OFDM调制解调仿真系统，模拟了整个系统的信号流程，进行了OFDM仿真系统参数的选择和调制模块的仿真设计、论证各算法性能，并根据各种不同的条件：例如高斯噪声、多径衰落、有无保护间隔等，对系统的误码特性进行了评估，为正确评价实际OFDM系统的性能提供了有效的理论依据。4、论文以软件无线电思想作为指导，提出了以256点IFFT／FFT为核心和以512点IFFT／FFT为核心的两种OFDM算法模式并存于同一个硬件平台、且可预选的方案，它们在参数选取和性能指标上有所差异，均实现了相似的模块和功能。5、论文参考IEEE 802.16无线网络标准的参数设置，针对本设计系统的应用环境和系统硬件的性能速率，提出了一种应用于实验室环境的信号结构、帧格式等参数设计。6、论文基于TI公司的6701evm数字评估板卡，结合模拟前端搭建数字中频平台，设计了基带处理的DSP软件模块并进行系统调试，基本实现了一套完整的OFDM调制解调方案。

For small chip size and low power consumption,the phase to sine mapping data is compressed using sine symmetry technique,sine-phase difference technique,quad line approximation technique,and quantization and error read only memory technique.

为了减小芯片面积和降低功耗，采用正弦对称技术、modified Sunderland 技术、正弦相位差技术、四线逼近技术以及量化和误差ROM技术对相位转正弦的映射数据进行了压缩。

The difference between quasi Shannon interval wavelet method and quasi Shannon wavelet method in the numerical approximation was compared by a concrete example.

因此该方法在解决不规则区域的偏微分方程上有显著优点。

After the deduction of high order temporal and special difference approximation to the wave equation, the snapshots of wave propagation in an infinite monoclinic media and synthetic three components surface and VSP data for a flat layered model are presented.

推导了交错网格中时间和空间上的高阶差分近似公式，并针对二维单斜各向异性介质，给出了具体的空间差分网格的形式。在上述理论的基础上，利用交错网格高阶有限差分技术，首次对单斜各向异性介质中波的传播特性进行了模拟。

He has to relate with three women in the movie, and yet remain implicitly faithful to the unseen Lucinda.

让克劳德布里亚里成功地饰演试验了一个难度很大的角色：和三个女人打交道，但还要底下对观众未曾谋面的卢馨达保持忠诚。

The experiment was conducted to study effects of inulin on the growth performance, indices of immune organs and serum immunoglobulin of laying chicklings as well as the performance of inulin which replaced the antibiotics in diets by adding 0.2%, 0.4% and 0.8% of inulin, respectively.

试验旨在通过在蛋用雏鸡日粮中添加0.2%、0.4%和0.8%的菊粉，研究菊粉对蛋雏鸡生长性能、免疫器官指数和血清免疫球蛋白的影响，以及菊粉替代抗生素对蛋雏鸡的应用效果。