查询词典 calculus of approximations

It was also found that the estimation of incident energy associated with energy transfer to the surface adatom could be employed in guidance of the experiments, although some approximations were introduced in the proposed model.

尽管在计算模拟中引入了一些近似，公式中也没有考虑离子、原子流比值和温度效应，但是，离子向表面增原子能量转移的近似计算结果，仍具有指导实验的预言性和适用性。

Problems of accurately computing algebraically exact solutions in the presence of rounding errors and of computing discrete approximations of solutions which are defined on the continuum.

在面对由连续性定义的误差与解的离散近似计算时代数学上的精确求解问题。

At the early 1980s, is an effective mathematic tool to deal with the uncertain or fuzzy knowledge. Rough rule theory has been widely used in information retrieval, digital library, software engineering and knowledge discovery. Its main idea includes acquisition of rough decision rules by reduction of data under the condition of keeping an invariability of classification capacity. And it basically represents a concept by a pair of approximation sets according to the partition on the given data based on the indiscernibility relation. Rough sets theory is well suited to deal with inconsistency of the rough approximations. So it is a new mathematical tool dealing with vagueness and uncertainty, and has found its applications in many areas such as AI, KDD, pattern recognition and classification and fault diagnosis.

主要完成了以下几个方面的工作：(1)对于高速移动机器人车道线跟踪问题中的规则知识获取，首先阐述了模糊逻辑系统的基本特点、工作原理和基本作法，分析了模糊规则知识获取过于依赖专家经验知识、对于每一个细节几乎都需要人工主观经验的参与、难以处理大数据集样本等方面的不足，进而阐述了粗糙集合理论的基本特点、基于粗糙集合理论的规则获取的关键技术和工作原理，为后续章节中经典粗糙集合模型的扩展及粗糙决策规则集的性能分析做好基础；(2)在经典粗糙集理论及其一般扩展的可变精度粗糙集VPRS的基础上，提出了非均匀可变精度粗糙集模型k-VPRS。

Some further approximations lead to a simple formula that expresses the barrier for nonidentity and identity hydrogen abstraction reactions as a function of the bond strengths of reactants and products.

第八章利用从头算价键计算方法结合价态相关图模型研究了卤族非等同氢提取反应，并对此类非等同氢提取反应做了归纳，推导出描述此类化学反应的能垒的普适半经验公式。

In a 1997 interview, Plass told me,"all sorts of things came together" that placed him at the scientific forefront: new detailed laboratory measurements of the absorption bands of water vapor, carbon dioxide and ozone; theoretical developments involving the influence of temperature and pressure on infrared absorption; new information about the carbon cycle and industrial emissions; and access to a new high-speed electronic computer to facilitate complex calculations of radiative transfer that replaced the older, graphical approximations.

在1997年的一次采访中，普拉斯告诉我：&所有的事情都赶在一块儿&，把他推到了研究的最前沿：测量水蒸气、二氧化碳和臭氧的吸收光谱带有了新的实验方法；温度和压强对红外吸收的影响理论有了新的发展；碳循环和工业废气排放有了新的资料；新的高速电子计算机代替了老式的图解近似法，让辐射传热的复杂计算变得简单了。

This paper discussed almost everywhere upper semiconvergence of optimal solution set of empirical approximations for stochastic programs.

本文对随机规划经验逼近最优解集的几乎处处上半收敛性进行了研究。

Firstly, an empirical approximation model of stochastic programming is obtained by replacing the probability measure of original program with empirical probability measure. Sequentially, the constrained stochastic programming is transformed into an equivalent unconstrained stochastic programming. Finally, using the epi-convergence theory, the almost everywhere upper semiconvergence of optimal solution set of empirical approximations for stochastic programming is obtained.

首先通过经验概率测度替代初始规划的概率测度得到随机规划的经验逼近模型，然后将带有约束的随机规划问题转化成与其等价的无约束的随机规划问题，最后利用上图收敛性理论，给出了随机规划经验逼近最优解集的几乎处处上半收敛性。

Some unknown elements always exist in the analysis process for the control systems, such as unmodeled dynamics, parametric uncertainties, change of the operating environment, model reduction and linearization approximations, etc., or external disturbance.

在对实际控制过程的分析过程中，总有一些未知因素存在，诸如未建模动态、参数不确定性、工作环境的变化、降阶及线性化近似等，也包括外部干扰的不确定性。

However,these approximations yield anisotropy so that the performance of the edge detection deteriorates.

但这些梯度近似值受边界方向的影响较大，降低了边界检测的性能。

Under this condition, a voxel always subtends a very small viewing angle, and a purely direction dependent representation of shading information is thus sufficient to produce accurate visual approximations of its projection.

在这种情况下，一个体素经常包含在一个十分小的可见角下，一个完全方向相关的表达用于着色可以产生它的投影的近似的精确效果。

You can snipe the second and third union leaders from this position.

您可以鹬第二和第三工会领袖从这一立场出发。

Aiming at the currently shortage of XML streams quality detecting, this paper proposes a new forecasting method of XML streams quality by least squares support vector machines, which is used the method of XML keys' vector matrix as windows, and vector product wavelet transform to multilevel decompose and refactor the XML streams series, that can fulfill real-time checking demand of XML quality, and ensure constraint, consist- ency and integrality. For even more adapting net load, it proposes a control strategy by weight and adaptive adjustment to ensure XML streams quality.

针对当前XML数据流质量检测存在的不足，提出构建XML键的矢量矩阵作为窗口，利用矢量积小波变换多级分解与重构XML数据流，再结合最小二乘支持向量机对XML数据流质量进行预测的一种方法，满足XML数据流质量重构时实时检测的要求，保证XML数据的约束性、一致性与完整性；为了更好的适应网络负载，采取加权与自适应窗口调整等调度策略充分保证XML数据流的质量检测。