上理想

Pseudo-random multi-frequency signal is invented and named by academician He Jishan. The bandwidth of PRMF signal is controllable, it's energy concentrates on several frequencies, which are equally spaced on log scale coordinates.

何继善院士发明和命名的伪随机多频信号，由于其带宽可控，能量主要集中在数个在对数坐标上呈等间距分布的频率上，是电法勘探的理想场源。

Pseudo-random multi-frequency signal is invented and named by academician He Jishan. The bandwidth of PRMF signal is controllable, it's energy concentrates on several frequencies, which are equally spaced on log scale coordinates. It is ideal excitation source for electrical exploration.

中文题名伪随机多频电磁法观测系统研究副题名外文题名 The study on pseudo-random multi-frequency electromagnetic prospecting system 论文作者陈儒军导师何继善学科专业地球探测与信息技术研究领域\研究方向学位级别博士学位授予单位中南大学学位授予日期2003 论文页码总数165页关键词电法勘探电磁法伪随机多频信号馆藏号BSLW /2003 /P631.3 /4 伪随机多频信号由何继善院士发明和命名，该信号带宽可控，其能量集中在数个在对数坐标上呈等间距分布的频率上，是电法勘探的理想场源。

Time flies, and Douzhuanxingyi, we look back at the nursing posts through the day and night, doing little Didi, this moment, we feel that we more clearly the ideal plug in the wings, reawakens the vitality of youth, full of life Hope.

光阴荏苒，，斗转星移，回首着我们在护理岗位上度过的日日夜夜，所做的点点滴滴，这一刻，我们更加清晰地感觉到我们的理想插上了翅膀，青春焕发了活力，生活充满了希望。

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。

Mirror finished behind a pendant, so just take back home at an ideal location, Dingshang linked to plug socket to start the switch, it can work, is very simple.

成品镜背后有挂件，所以只需拿回家里置于理想位置，钉上挂钩，插上插座，启动开关，就可以工作了，非常简单。

The surface planishing and 1mm diameter (where the soil sample passing through 1mm standard griddle) are idealer process and appropriate diameter selection for measurement indoor, because they have lesser standard error vector of testing direction and average reflectance in repeated measurements for soil with different texture.

表面压平处理方法及1mm粒径条件下，不同质地的土壤总体上都能获得具有相对较小的测试方向上的标准差向量及多次重复测试反射系数平均值之间的标准差向量，是室内测试较理想的表面处理方法和合适的土壤粒径选择。

On the studies of three different assist characteristic of EPS, the method of founding curve type assist characteristic is discussed and the curve of assist characteristic is trained offline by neural network. And with the toolbox of MATLAB, the perfect expression of assist characteristic can be obtained.

本文对三种不同形式的EPS助力特性进行了理论上的分析，在离散助力特性研究的基础上，探讨了初步确立曲线型助力特性的方法，并提出以神经网络对助力特性曲线进行离线优化训练，通过MATLAB工具箱拟合得到了比较理想的电动助力系统的助力特性表达式。

The article presents the developing condition of PWM and SVPWM first.Then the theory of SVPWM is discussed in detail.The SVPWM is based on the thought of magnetic chain tracking.It makes the ideal magnetic chain circle of three-phased sysmmetry electric motor supplied by three-phased sysmmetry sine wave voltage for basis,uses the practical magnetic chain vector formed by the different switch modes of three-phased inverter to track the basic magnetic chain circle.During the course of tracking,the inverter changes the switch modes properly to form the PWM waves.Then the modulation wave of SVPWM is analyzed in detail.The modulation wave of SVPWM is implicit,but the analogous modulation wave in A-B-C axis needs to be calculated in order to expose the internal relation of SVPWM and SPWM.That is to show the implicit modulation wave of SVPWM. SVPWM actually is a transformed SPWM ruly sampled by the modulation wave which is injected by the zero prefaces based on space vectors.

本文首先对脉宽调制技术的发展现状进行了综述，在此基础上分析了电压空间矢量脉宽调制技术的发展现状；接着对空间电压矢量脉宽调制技术的基本原理进行了详细的分析和推导，SVPWM是基于磁链追踪的思想，它以三相对称正弦波电压供电下三相对称电动机定子理想磁链圆为基准，由三相逆变器不同开关模式下所形成的实际磁链矢量来追踪基准磁链圆的，在追踪的过程中，逆变器的开关模式作适当的切换，从而形成PWM波；然后详细分析了电压空间矢量脉宽调制技术的调制波，虽然SVPWM法的调制波是隐含的，但是为了揭示SVPWM法与SPWM法的内在联系，需要求出SVPWM在A-B-C坐标系上的等效调制波，也就是将SVPWM的隐含调制波显化；SVPWM实质是一种基于空间矢量在三相正弦波中注入了零序分量的调制波进行规则采样的一种变形SPWM。

Ideally, you'll hang onto the controller, rather than letting it sail gracefully across the room into a wall – how the SIXAXIS would interpret that is hard to say!

理想的情况下，你会坑上控制器，而不是任由它出海优雅地跨房间到墙壁上-如何s ixaxis会解释说，是很难说的！

Come 20 years, I give me to give a name without pa of implementation old A " gold is buckled " the expectation when, go up to live abundantly too, but the value that I realized people on one's own side to be born on ordinary post however, with a Communist's rock-firm belief, braided the anadem of life ideal.

二十年来，我没有实现老阿爸给我起名&金扣&时的期望，过上富有的生活，但我却在平凡的岗位上实现了自己人生的价值，以一个共产党人坚如磐石的信念，编织了人生理想的花环。

I will endeavour to find you some assistance.

我尽力帮你找人帮忙。

At first I only know bruck is the idol of American younglings, afterwards I returned back to Taiwan ,even in Beijing last year ,I saw her poster everywhere, I was so surprised at her charm.

起初我只晓得布鲁克雷德丝是美国少男少女崇拜的偶像，后来回台湾，甚至去年在北京，居然也四处看见她的海报，才惊讶她的魅力之大。