随机法

Both LDPC codes and OFDM technology are studied in this paper. The working and the results obtained are summarized as follow:1. The definition of LDPC codes and its coding/decoding ideas are systematically summarized, a general algorithm of changing any parity-check matrix to lower triangular form, which is suitable for quick encoding, is given out, along with a girth checking algorithm. Absolutely random LDPC codes construction is improved, a new half random construction of LDPC codes with linear time coding and no 4-cycles is brought out.

系统地阐述了低密度校验码的定义及编译码原理，提出了一种将任何校验矩阵变换成适于快速编码的近似下三角形式的通用算法及一种围长检测算法，对完全随机的校验矩阵构造法进行了改进，提出了一类消除4环且可近似线性编码的校验矩阵半随机构造法，仿真表明，在高编码效率情况下，改进后的半随机构造法，其性能稍优于完全随机构造法，并可以线性时间编码，因此更适合实际应用。

Considering the randomness of the structural physical parameters and utilizing the random variable's functional moment method and the algebra synthesis method, the mean value and the variance of the mean square value of the structural displacement response under stationary random excitation are computed firstly from the expressions of structural stationary response in frequency domain. And then the expressions of the mean value and the variance of stochastic rigid frames dynamic reliability are educed from the Poisson formula of calculating dynamic reliability.

考虑结构的物理参数具有随机性，从结构随机响应的频域表达式出发，利用求解随机变量数字特征的代数综合法和矩法，导出随机参数刚架结构在平稳随机激励下的位移及速度响应均方值的数字特征，再由动力可靠性的Poisson公式导出结构动力可靠度的计算公式。

Therefore, basic methodologies for stochastic seismic and filtering responses of nonlinear structure are studied, the approximate solution methodologies and their practical applications are investigated in the dissertation employing equivalent linearization and moment equations method based on FPK equations and Ito stochastic differential equations. The research works are mainly concerned with the following aspects:Firstly, the differential expression of bilinear hysteretic is studied and a new differential expression is developed, then they are demonstrated.

因此，本文基于FPK方程和伊藤随机微分方程，研究了滞后结构物的随机地震反应和随机滤波问题的基本方法，并利用等效线性化法和矩方程法，研究了非线性结构随机地震反应分析和随机滤波分析的近似解法及它们的工程应用。

Methods 80 somatization disorder patients were divided into study group and control group.

采用入院顺序分层随机法，将80例躯体形式障碍患者平均分为研究组和对照组。

Methods 80 post-menopause women with recurrent urethral infection were divided into two groups randomly.

80例有复发性尿路感染病史的绝经后妇女随机法进入实验组和对照组。

Methods Forty-four Wistar rats were randomly divided into sham operation group (SO group, n=12), operation group (n=16) and carbachol treated group (carbachol group, n=16, carbachol 50 μg/kg). Animal model of abdominal adhesion was established by rubbing the procussus vermiformis of cecum with dry sterile gauze, and by clamping and scuffing abdominal wall.

44只雄性Wistar大鼠按完全随机法分为假手术组(n=12)、手术对照组(n=16)及卡巴胆碱组(n=16，卡巴胆碱50 μg/kg)，后2组采用开腹后无菌干纱布摩擦大鼠盲肠蚓突部，钳夹和刮伤腹壁法制作大鼠腹腔粘连动物模型。

There were 2 cases of aspiration pneumonia in control group, 1 in group A, 1 in group B and 0 in group C.

完全随机法[1] 分为四组，每组 4例病人，干预 1个月，每组鼻饲 4 80次，4组病

Methods Thirty-eight patients with mild to modcrate periodontitis were debrided using both A.system(VectorTM-system)and B-systemSuprasson P5 Newtron(Rin a split mouth design.At baseline,one month after treatment,plaque indexand bleeding on probingwere recorded and probing depthWas measured.

选择38例轻、中度牙周炎患者，对患者口内一、四象限用奇数、偶数随机法选择AVector治疗仪，德国D(URR齿科公司或BSuprasson P5 Newtron(R超声多功能牙科治疗仪，法国赛特力公司超声治疗仪进行治疗，第2天对二、三象限使用另一系统进行治疗。

Cases of acne patients were randomly divided into 2 groups (n=20), treatment group and medicine control group.

选择40例女性痤疮患者，采用简单随机法分为治疗组和对照组，各20例。

In studies with small sample sizes, imbalances between the two groups can easily occur despite randomisation.

在小样本研究中，尽管采用了随机法，但两组间偏倚还是很容易发生的。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。