查询词典 variation method

The following conclusions have been made in this paper.(1) Based on CO_2 flux data of eddy covariance, variation characteristics of gross primary productivity in four flux observation stations were studied, which are an alpine meadow, an alpine shrub meadow, a swamp alpine meadow and a steppe alpine meadow at Dongxiong. The results show that photosynthetic capacity of the alpine meadow is the highest, and the annual total GPP is 652.2g C/m~2. Daily-differencing approach is used to analyze the random error of CO_2 fluxes measurements. The results show that the distribution of random error follows more closely follows a double-exponential, rather than a normal distribution, capturing the high peak and thick tail, and the random error varies with environment variables, which violates the assumptions for the ordinary least squares fitting with normality and homoscedasticity, consequently, we introduce maximum likelihood method for parameter optimization.

本文主要在以下几个方面开展工作并获得了一些认知和结论：(1)通过分析样带区域内高寒草甸、高寒灌丛、沼泽化湿地和草原化高寒草甸四个通量观测站点草地生态系统总初级生产力变化特征，研究结果表明HBBT矮嵩草草甸生态系统植被光合作用能力较强，年GPP总量为652.2 gC/m~2，明显高于其他三种生态系统；通过利用"单塔日变化法"获得四站点通量观测数据随机误差，结果表明通量观测随机误差概率分布呈现尖峰厚尾的特征，与正态分布相比，更服从双边指数分布，进一步分析表明通量观测随机误差随环境变量(风速、温度和光合有效辐射)的变化而变化，这违背了普通最小二乘法进行生态过程模型参数优化正态分布且误差同质的假设，因此本研究中引入最大似然法进行生态过程模型参数优化。

This paper researched the inheritance and variation of growth rate, colony morphology, sporulation and homothallism of Phytophthora sojae with classic genetics method.

采用经典遗传学方法研究大豆疫霉菌单孢后代的菌丝生长速率、菌落形态、产孢量以及同宗配合性状的遗传变异，以期为有效控制大豆疫病的发展和蔓延奠定基础。

On the basis of variation characteristics of ship speed error model, a ship speed regulator using the on-line adaptive error model is proposed in this paper. The control scheme is based on back propagation multi-layer perceptrons adaptive neural network in which a modified hyperbolic tangent function is used as the activation function of an auto-tuning neuron and is updated by the steepest descent method.

在分析船舶航速误差模型变化特性的基础上，应用激励函数的自适应神经网络和最陡下降法的非线性优化技术，提出了自适应学习误差模型控制方法，应用于船舶柴油机调速器控制系统。

The 3 order Yeoh constitutive model is used to describe the mechanical behavior of carbon-filled rubbers, the aging deterioration rule of carbon-filled rubber is discussed by thermal aging test, and an incomplete quadratic polynomial model is established by Response Surface method, which can describe the variation of performance with aging time and temperature of aged rubber.

用响应函数法建立了橡胶性能随老化时间、温度变化的二次不完全多项式模型，定量描述了材料热老化性能的变质规律。

Aneurysms generally make use of being deposited with coil in clinic. The effects no growth 、 treatment and rupture of the aneurysm are indistinctness. The article's motive is to simulate effects before and after coiling in different volumetric ratio by computation method. We discovered that the results of the wall shear ratio and wall pressure were no variation before and after coiling.

动脉瘤置入线圈在临床医学以被广泛用於治疗，由以往文献可知在动脉瘤之成因、成长、破裂、治疗等过程之重要因素还不甚了解，本文藉由数值方法模拟放置线圈前后及线圈占动脉瘤之不同体积比之影响，其发现在放置线圈前后壁面压力及剪应力并无明显变化。

The method of slide-mode variable structure control is such a strategy that is characterized of low mathematical model precision, insensitiveness to system parameter variation and external disturbances, omission of parameter identifications, fast dynamic response and easy implementation. These advantages make it suitable to high performance vector controlled AC motor drives.

滑模变结构控制是一种强鲁棒性的控制方法，对系统数学模型精度要求不高，具有快速响应、对参数及外部扰动变化不敏感、无需系统在线辨识，实现简单而且很适合计算机实现等优点，因此，很适合高性能的交流电机矢量控制系统。

General method of inpainting is to interpolate. In this chapter, image inpainting based on total variation is focused on.

常用的图像修描方法是插值，本章研究了基于全变分模型插值的图像修描方法，结合图像增强模型提出了同时对图像进行局部修描和增强的方法，并提出了修补纹理图像的算法。

The equations of a high-speed rotating plate are obtained using Jourdain＇s velocity variation principle and the finite element method and MTA are used for discretization.

基于Jourdain速度变分原理，先推导出做高速旋转薄板的动力学连续变分方程，再用有限元法对柔性薄板进行离散。

This research concentrates on the optimal factor selection of this modification with Kolmogorov test. The factor is a constant for all tolerance. This optimization method can bring a significant reduction of the difference between variation analysis and tolerance analysis. The thesis presents a framework to model and evaluate assemblies and their assembly process for autobody structure concept design. This framework makes the autobody structure concept design more science-based than experience based, and will significantly enhance the dimensional quality of autobody assemblies.

本文的研究以理论推导、数值模拟为主，结合生产实际数据的对比分析，在前人研究的基础上提出了并行车身结构概念设计方法，将依据经验的车身结构概念设计上升为依据严密数学推理和运算的过程，为进一步提高车身的尺寸质量提供了新的思路，同时对飞机、家电等薄板装配机械产品的设计和质量控制也具有重要的借鉴意义。

It can solve seismic velocity problem in the area with lateral strong velocity variation. A new method is developed to improve the precision of velocity model building.

从射线理论的程函方程出发，提出了一种没有过多理论条件约束的基于模型全局优化剩余曲率分析速度建模方法，理论和实际资料的计算证明了该方法的有效性。

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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。