查询词典 weighted mean

In the present study, only T2-weighted images were aailable for assessment; T1-weighted images had been taken in the axial plane for measurements of erector spinae muscle size,24 and it was not feasible to also obtain T1-weighted sagittal images.

在我们的研究中，仅有T2加权像被用来进行评定，我们做的轴面T1加权像被用来测量骶棘肌的大小了[24]，而同样也获得矢状位的T1加权像是不太可行的。

It can be show different characteristics in the MRI of the orbital diseases, the sheath of the orbital tumor contain certain characteristics, can express soft muscle locate the orbital compartment or outside. and the tumor showed hypointensity or hypo-or isointense mass on T1-weighted images, and iso-or hyperintense or hyperintense mass on T2-weiglited images, inflammation expresses for the orbital inside limit the soft muscle or widespreads excrescent signal, and showed hypo-or isointense mass on Ti-weighted images, and iso-or hyperintense mass on T2-weighted images, the companion contain fatty the eye muscle big or the eye wreath increase thick, the lachrymal gland is swollen.

其在MRI表现各具有影像学特征，眼眶肿瘤多表现为位于眼眶内、外的局限性软组织肿块，MR T1WI呈等或稍低信号，T2WI呈高或等信号多见；炎性假瘤则表现为眶内局限性软组织肿块或弥漫性异常信号，MR T1WI呈低信号，T2WI呈高信号，常伴有眼肌肥大或眼环增厚，泪腺肿大等。

The alternative estimators used in this paper include least squares estimator, stratified weighted least squares estimator, probability weighted least squares estimator, and Quasi-Aitken weighted least squares estimator.

中文摘要抽样调查设计随著资讯需求的增加日益复杂，然若参数的估计方法无法配合所使用的抽样调查设计，则统计推论结果将难以达到预期的精确度。

In this paper, we first give an example that the bilateral weighted shift operator in c_0space is hypercyclic operator and first solve the existence problem of hypercyclic operator in c_0or c_0(Z space . And then we investigate the property of weighted shift operator in c_0 space and an important property of the hypercyclic vector of weighted shift operator in c_0 space and c_0 space. At last we give the concept of weak hypercyclic operator and weak hypercyclic vector , and give the equivalence between the weak hypercyclicity and the hypercyclicity in l~1 space.

本文首先给出了c_0空间上的一个双边左加权移位算子是超循环算子的一个例子，首次解决了c_0 或c_0(Z 空间中超循环算子的存在性问题；接下来分别研究了c_0和c_0空间上的加权移位算子的性质以及c_0和c_0空间上的加权移位算子的超循环向量的一个重要性质，最后提出了弱超循环算子和弱超循环向量的概念，并且给出了I~1空间中弱超循环性与超循环性的等价性。

Results:Most of the intracranial chordoma（16 cases in our group,88 9%）were located in the middle area of the skull base such as clivus and/or sellar region and always invaded extensively the nerves and major in tracranial vessels of skull base.All tumors were hypointense on T1- weighted imaging and heterogeneous hyperintense on T2- weighted imaging,On Gd- DTPA contrast- enhanced T1- weighted imaging 8 chordomas enhanced more markedly,but steady heterogeneous.

结果：颅内脊索瘤大部分（本组16例，占889%）发生于颅底中线处的斜坡和/或鞍区，并广泛侵犯颅底的神经和大血管等重要结构；在T1加权像上肿瘤主要表现为低信号，T2加权像上表现为不均匀高信号，Gd-DTPA静脉注射增强后（8例）均出现较明显的不均匀强化。

The MR protocol involved transverse, coronal, and sagittal noncontiguous T2-weighted single-shot fast spin-echo sequences; transverse fat-suppressed T2-weighted fast SE sequences; transverse T1-weighted gradient-recalled-echo sequences; and transverse and coronal short inversion time inversion-recovery sequences performed through the lower abdomen and pelvis.

MR计划包括于下腹部与骨盆位置执行的，横轴的、冠状的、矢壮轴的非连续T2加权单射快速环绕音波程序；横轴压抑脂肪讯号的T2加权快速SE程序；横轴T1加权梯度回复音波程序；以及横轴、冠状短程反向时间反向回复程序；由2位放射科医师评估MR结果，以及与外科及病理发现、临床追踪数据比较。

Then we real result which can reflect the momentum profit .Our analysis indicates that : the liquidity—weighted investment portfolio can get more profit than equal-weighted investment portfolio, even after adjusted by price impact cost; but its profit fall behind in the market- value-weighted investment portfolio.

我们的实证分析结果显示：流动性加权投资组合的确能够获得比以往研究中广泛使用的等权重组合更好的收益，即使在价格冲击成本调整后仍然如如此；但其收益表现却一直弱于市值加权投资组合的收益表现，这个结果是和国外成熟市场的研究结果是相反的。

The numerical results also indicate that the weighted geometric mean method needs less number of iteration than the weighted arithmetic mean method.

数值结果也显示：加权几何平均法所需的迭代次数比加权算术平均法所需迭代次数少。

Based on investigating the short and intermittent structural plane, surrounding rockmass of the huge underground powerhouse in Three Gorge has been divided into five statistical similar areas according to its characteristic of rockmass structure by applying structure plane network simulation. Distributed characteristic of structural plane has been studied and based on it mechanics macrocharacteristic has been studied:(1) It is the first time that based on the result of structural plane network simulation rockmass quality of every structure area has been studied with applying blurred information optimum seeking technique and be compared with and RQD method. The result indicated that it has better effect to evaluate rock quality with blurred information optimum seeking technique.(2) It is the first time that the interrelated relationship of the result of in-suit rockmass deformation test and fractal characteristic of structure on test point has been applied to determine rockmass deformation parameter. The question of evaluating deformation parameters of engineering rockmass has been solved.(3) Anisotropy strength parameters have been determined by applying shear zones simulating method. The result indicated that there are different strength parameters in every structural area, after comparing the result of Fast Lagranian Analysis in continua number simulation method with that of method of weighted mean according to continuity. The result indicated that when a suitable reduction coefficient is been considered rockmass strength parameters can be simply and fast determined with method of weighted mean according to continuity where there is not enough test result.(4) Damage characteristic has been studied based on analysis fractal characteristic of structural plane network by applying fractal-damage coupling method. It is the first time that the concept of damage degree has been set up to evaluate rockmass quality according to the biggest principal damage.

通过对短小、断续性结构面统计特征的研究，将地下厂房区划分为五个岩体结构统计均质区，应用结构面网络模拟技术研究了各个岩体结构均质区结构面的发育分布特征，并以此为基础对岩体宏观力学特性进行了深入研究：(1)首次通过在结构面网络模拟计算结果的基础上，应用模糊信息优化技术研究了厂房区各个岩体结构分区的岩体质量并与岩体基本质量指标研究法、岩体质量指标RQD值研究法作了对比，结果表明以结构面网络模拟结果为基础，应用模糊信息优化技术进行岩体质量评价能够取得很好的效果，解决了工程岩体质量的定量评价问题；(2)首次通过对已有的现场大型岩体变形试验结果的分析及相应试验点岩体结构分形特征的研究，建立了结构面分布的分形维数和岩体变形指标间的相关关系，并首次应用这种相关关系根据结构面网络模拟及分形维数计算结果确定了缺少试验结果的地下厂房各工程部位的岩体变形指标而且应用于围岩稳定性计算，解决了工程岩体宏观变形参数的评价问题；(3)应用在结构面模拟网络图上模拟岩体剪切破坏带的方法，得出了岩体在不同方向上的强度参数，结果表明岩体的强度特性与结构面的发育方向和程度有着明显的关系，各个岩体结构均质区具有不同的强度参数；同时还通过应用拉格朗日差分法对岩体强度指标的数值分析并与按连通率加权平均计算法对比表明，按连通率加权平均计算法在考虑合理的折减系数情况下，可以简单快速地对缺少现场大型试验结果的具体工程部位实现岩体强度指标的估计，通过以上研究解决了工程岩体抗剪强度参数的评价问题；(4)通过结构面网络分形维数的研究，应用分形损伤耦合分析方法，研究了厂房区岩体的损伤特征，并首次引入"损伤度"的概念，建立了应用最大主损伤评价岩体质量的指标体系。

Through simulation,the maximum root mean square value of weighted acceleration and the root mean square value of total weighted acceleration of given points are obtained directly.

通过仿真可直接获得给定测点的加权加速度均方根值分量的最大镇和总加权加速度均方根值。

The work of this paper is as follows: 1. Looking back the progressing history of the linear motor, introducing the features of the elevator driven by linear induction motor, radicating the topic of this paper "the digital frequency variable control of the elevator bi-side direct driven by linear induction motor". The research of this paper covers the conventional VVVF control, space vector based VVVF control, vector control and DTC.

本文主要开展了以下几个方面的工作： 1 回顾了直线电机发展历史，电机的驱动技术演变，特别是针对直线电机的驱动，简要介绍了直线感应电机驱动电梯的优点和不同结构类型，对传统的v／f控制，基于空间矢量法的v／f控制，矢量控制，和基于电压空间矢量的直接转矩控制进行了比较，确立了本课题的研究主题：直线感应电机双边直推式驱动电梯的全数字变频控制。

The article combines with the treatment of a superficial civil air defense work to introduce how the grouting method to improve the performance of the backfill soil.

文章从治理漂浮人防工事的角度提出了注浆技术在改善回填土性质方面的应用，并详细阐述了注浆技术的施工流程。