总体参数

The sampling of complicated materials were investigated. The relationship between the composite sampling variance and the number of increments was studied. The quantitative equation for estimating the composite sampling errors directly from the physical and chemical parameters of the population with multinomial distribution theory was presented. Monte Carlo simulation technique was employed to verify the above theories.

对于复杂物质的取样，研究了分层性物质的组合取样误差与份样数目之间的关系；采用多项分布理论，提出了组合取样误差公式，建立了组合取样误差与被研究总体的理化参数(如组分含量、质量分数等)之间的定量关系，通过Monte Carlo模拟技术对此进行了验证。

The design features, general arrangement, performance parameters and test and operation of SDD1A narrow gauge diesel-electric locomotive delivered to Sudan Railway were introduced in detail.

详细介绍了交付苏丹铁路的SDD1A型窄轨电传动内燃机车的设计特点、总体布置、性能参数及试验运用情况。

Considering the low effective of GARCH model for high frequency data,the nonparametric method is adopted to estimate the value at risk of high frequency data.

文章在GARCH模型对高频数据低效的情况下，从非参数的角度给出风险价值一个相合估计量，这个估计量不依赖于总体分布。

The validity of simulation results were tested by experiments. Through statistical analysis, the parameter (μ,σ2) of normal distribution function of the maximum load, and tested uniformity of the normal population and the sample were obtained.

在此基础上，随机生成200个典型海底地形，对采矿头截齿最大载荷的分布特性进行研究；应用置信度为0.95的柯尔莫哥洛夫斯米尔诺夫(Kolmogorov-Smirnov)检验验证参数估计所得的正态总体与样本数据的一致性。

The whole structure, parameters and working mechanism of the ultrasonic on-line testing equipment was completely analyzed and recognized.

对设备进行了全面的剖析，理解了引进的超声波在线检测设备的总体结构、参数及探头系统的工作原理。

This design considerations give the parameter in line with the passing in principle and calculating the overall scheme which is confirm the transmission department strictly of applicability, it has not only reduced the operator's working intensity greatly but also make the complete machine performance improve a lot.

本次设计依据所给参数本着适用性的原则通过严格计算确定了传动系的总体方案，其不仅大大减少了操作人员的工作强度，而且使整机性能有了很大提高。

In order to think about unbiasedness, we need to rewrite our estimator in terms of the population parameter

为了考虑无偏性，我们需要用总体的参数改写

In this paper,with respect to the ordinal variables,the definitions of attribute reduction of dominance-based rough set approach in ordered information systems and ordered decision tables are given.Then the approach of sorting objects comprehensively using rough set theory is brought in to obtain a series of ranks.Based on these ranks,nonparametric methods to analyze correlation between two attribute subsets are introduced,and Spearman rank correlation coefficient is used as a measure of attribute correlation.Based on this measure,a new method of attribute reduction of ordered information systems and ordered decision tables is presented without changing the ordinal information of the universe.

针对有序尺度变量，给出了有序信息系统与有序决策表在优势关系下的粗糙集约简定义；利用粗糙集方法将对象综合排序，进而得到一组秩；根据这些秩，运用非参数统计的思想研究了两个属性子集之间的相关性，并将Spearman秩相关系数作为属性相关性度量；在不改变总体序信息情况下，给出了基于此度量对有序信息系统与有序决策表进行约简的新方法。

Many researchers have devoted their work to the development of modal analysis extraction techniques in order to obtain more reliable identification of the modal parameters. There are many damping identification methods, but each one has different merit and defect. In order to find which one is the most reliable method with respect to certain characteristics, this thesis focus on how to identify structure's damping in time domain. The following works have been done in this thesis: 1. Investigate four modal analysis methods——the LSCE Method, the Ibrahim Time Domain Method, the Time Domain Collectivity Modal Parameter Method, the Rational Fraction Polynomial Method and improve on the ITD Method in arithmetic.

本文主要做了如下工作： 1、集中研究了四种常用的模态识别方法，即最小二乘复指数法、Ibrahim时域法、时域总体模态参数辨识法及有理分式多项式法，并对ITD法在算法上进行了一定的改进； 2、建立结构动力模型，利用这四种方法在具体条件下识别结构的阻尼，并绘制相应的图； 3、讨论不同的情况下，不同的识别方法对阻尼识别精确性的影响； 4、基于业已明确的阻尼识别的精确性，根据研究的需要，指出在实际的识别过程中，如何选择最佳的识别方法以及识别过程中需要注意的问题； 5、选择最为精确的阻尼识别方法，以导师李书进教授在日本京都大学防灾研究所强震反应实验室所做的一足尺木制结构房屋的动力测试实验为实测模型，识别其阻尼； 6、在本文的最后，尽作者所知，提出了一些需要改进的地方，并对未来的研究方向给出了作者的建议。

Carrier-based aircraft ; catapult takeoff ; conceptual design ; numerical simulation ; parameter match ; safety criteria

舰载飞机；弹射起飞；总体设计；数值仿真；参数适配；安全准则

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。