查询词典 multilevel

The high-voltage high-power multilevel converter and AC motors drive techniques are summarized compendiously for domestic and overseas studies in the prolegomenon of this dissertation. The evolution and research status of multilevel converter topologies are analyzed, the development of AC variable speed techniques and the characteristic of DTC are discussed, also, the aim and significance for the research are demonstrated. In this dissertation, SVPWM pattern and implement method have been addressed comprehensively for three-level NPC inverter.

本文绪论部分针对国内外高压大容量多电平变换技术和交流传动控制技术作了简要综述，着重分析了多电平拓扑结构的发展和研究现状，讨论了交流调速的发展和直接转矩控制技术的特点，指出本文选题的目的和意义。

In this paper, the application of the multilevel invertor and the development present condition of multilevel invertor circuit and control strategy is introduced firstly.

本文首先介绍了多电平逆变器的应用，以及多电平逆变器电路拓扑结构和控制策略的发展现状。

Through analysis to multilevel invertor a method of switching angle control for Diode-clamping Multilevel Inverter is introduced. The quantity of wave for output voltage is improved and the content of harmonics is reduced. And a design is carried on to realize the control mode based on TMS320F2407DSP.

通过分析多电平逆变器的拓扑结构，选择二极管箝位型多电平逆变器为研究对象，提出在二极管箝位型逆变电路中实现开关角控制的方法，该方法减少了谐波的含量，改善了输出电压的波形，并以TMS320F2407DSP为平台进行了设计实现了该控制策略。

A new multilevel relation hierarchical model with element level labeling is proposed in this paper, which is capable of processing multilevel spatial data.

本文提出了为每一元素赋予安全级时的多级关系-层次数据模型，该模型能处理多级空间数据。

Methods. Eleven patients (six men, five woman; mean age 72.8±6.3 years) presenting with refractory neck pain and progressive multilevel cervical radiculopathy and/or myelopathy due to cervical spondylosis with spinal canal and neural foraminal stenosis underwent multilevel laminectomy, foraminotomy, and subsequent instrumented posterior fusion via bilateral or unilateral percutaneous muscle dilation approaches.

11例患者，男6例，女5例，平均年龄72.8±6.3岁，表现为顽固性颈痛，进行性的颈椎神经根和脊髓压迫症状，椎管和椎间孔狭窄，通过双侧或单侧经皮肌肉扩张法，对这些病人进行多节段椎板、椎间孔减压，后路融合固定。

The method of multilevel parallel phase modulation was proposed, which means two parallel multilevel phase shift keying signals were transmitted with one frequency at the same symbol period.

提出了高阶并行相位调制的方法，即在同一调制符号周期，使用同一频率、并行发送2路携带不同信息的高阶相位调制信号。

Multilevel-based VLSI partitioner is proposed and implemented,named MVP.

基于多水平方法，设计并实现了一种VLSI剖分系统（Multilevel-based VLSI Partitioner，MVP）。

Hierarchical linear modeling is the most frequently used technique for analyzing multilevel data. In this paper, the twelve key issues in multilevel research and/or using HLM software were reviewed, and provided their exact meanings and feasible solutions. The 12 key issues included intraclass correlation coefficient, sample sizes, formation of organizational constructs, centering problems, fixed effect and random effect, estimation methods, goodness of fit index, explained variation, multicollinearity, robust standard error, level one variance equation, and empirical Bayes estimates.

本文针对阶层线性模式在多层次研究上有关於技术、测量与方法论所遭遇的问题，进行文献整理并讨论其实务意涵，并依据使用时机、抽样议题、资料汇总、分析方法、与模式评估与估算等五方面整理出十二项重要议题与解决之道，包括：组内相关系数的意义与判断准则、多层次研究各层的样本数问题、变数聚合成组织层次问题、中心化的意义、固定效果与随机效果的设定、估计法的选择、适配度的比较、解释变异量的计算、多元共线性的分析、强韧性标准误、第一层误差项变异数与实证贝氏估计值的运用。

Aiming at the problem that the payloads of local servers are tempestuously fluctuating along with the movement of amount of on-line user in the video grid of multilevel architecture because the absence of temporary servers,the video grid of mixed architecture based on the video grid of multilevel architecture and the peer-to-peer technology is produced to transmit video stream data between the normal clients directly.

针对可扩展视频网格结构中，由于加盟服务器数量不足所引起的区域服务器负载波动随在线用户数量变化过大的问题，引入P2P技术构造混合结构的视频网格，实现普通客户端之间视频流数据的直接传输。

Cascade multilevel converter is made up of modules. It can be normally divided into two kinds: one with same modules and the other with different modules. This paper analyzes the relationship among the maximum number of output voltage level, the number of cascaded modules, and the input voltage ratio and THD of output voltage in different kinds of cascade multilevel converter. Then, some guidelines for making up cascade multilevel converter are given.

级联型多电平变换器类似于积木化的结构，本文按模块单元的结构形式，将级联型多电平变换器分为相同单元和不同单元两类，以输出最大电平数为目标，系统地分析模块单元个数与最大输出电平数、输入直流电压与最大输出电平数、以及输出电平数与谐波畸变率之间的关系，从中归纳得到构造级联型多电平变换器的指导原则。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。