下降函数

In the algorithm, radial-basis function neural network was utilized as forward model, and genetic algorithm was used to solve the optimization problem in the inverse problem, which can avoid the local minimum solution possibly encountered in the iterative inverse algorithm based on gradient descent and consequently achieve the global optimized solution of the inverse problem.

在该算法中，径向基函数神经网络用作前向模型，遗传算法用于求解逆问题中的优化问题，其优点是能够避免基于梯度下降法的迭代逆算法中可能遇到的局部最小问题，并能得到逆问题的全局最优解。

The macroscopic rheological parameters and microstructure parameters were closely related, it is helpful to explain the essence of multiple rheological properties through the analysis of which the wax evolution process and microstructure of the crude oil which is waxy and high viscosity; the yield time of gelled waxy crude oil monotone increases along with the decreasing of rate of shear (the time of stress effect prolonged), there was power function relationship between them, it can be expressed with ; when adding diesel oil to Sudan crude oil, dilute proportion bigger the eccentricity degree of paraffin particles were bigger too, that was to say the symmetry of wax crystal was better, the wax crystal form fabric more hardly when the intermolecular interaction was smaller; in the light of macroscopica, the fall extent of the abnormity temperature, solidifying point and viscosity could be larger along with the accretion of dilute proportion, as a result, it's rheological properties could be improved.

SD原油析蜡点为94℃，析蜡高峰为50～30℃，异常点为40℃；其蜡晶颗粒细小、对称性差，所以具有较大的比表面能，容易形成联生、联锁结构；损耗角曲线与储能模量曲线或损耗模量曲线的交点所对应的温度与原油凝点或倾点温度非常接近，大约在39℃左右；也就是说，含蜡原油粘弹特性曲线的交点可以表征其流动性；原油宏观流变参数与微观结构参数密切相关，原油析蜡过程及蜡晶微观结构分析有助于诠释易凝高粘原油多重流变特性的本质；胶凝含蜡原油的屈服时间随剪切速率的降低而单调增加，二者显然存在幂函数关系，可用关系式描述；当SD原油加柴油稀释处理时，稀释比越高，蜡晶颗粒的偏心度也越大，亦即蜡晶对称性越好，分子间作用力越小，蜡晶颗粒越不易形成结构，宏观表现为异常点、凝点及表观粘度等流变参数下降的幅度越大，流动性越好。

The results of numerical experiments, using the four-dimensional variational data assimilation system of the nonhydrostatic mesoscale model MM5, show that: the tangent linear model and adjoint model conducted by keeping the "on-off" switches the same as the basic state, can provide a good approximation of the first-order information to the NLM perturbation and a good descent direction for the minimization procedure; switching on and off at every other time step in the Kuo cumulus parameterization scheme don"t impact the convergence rate of cost function; the existence of the switches don"t impact improvement to the MM5 model rainfall prediction because that not only specific humidity ,but also wind, temperature and pressure are assimilated into the model.

非静力中尺度数值模式MM5的四维变分资料同化系统进行的数值试验结果表明："开关"变量保持与基态一致，所构造的切向线性模式能够提供关于非线性模式扰动的一阶近似，伴随模式所计算的梯度值能够为最小化过程提供较好的下降方向；郭氏降水参数化方案中对流每隔一个积分步的交替发生并不影响目标函数最小化的收敛速度；"开关"变量的存在也不影响将风、温度、气压和比湿结合起来同化对MM5降水预报准确性的提高。

In view of the principle of pointbypoint comparison method, the foundation deciding whether the middle point interpolation is the control step error of NC system has been advanced, the math mould of inserting and compensation method established and the function that judges error by interpolating method has been improved.

基于逐点比较法原理，提出中点插补算法作为数控系统控制步进的偏差判别依据，建立了插补算法的数学模型，对插补算法偏差判别函数进行了改进和完善。实例分析结果表明，中点插补算法使插补精度由原来的小于等于一个脉冲当量提高到小于等于 0 。5个脉冲当量，插补点大幅度地下降，系统的响应速度加快和插补精度提高

By using generalized projection matrix, conditions are given on the scalars in the three term-memory gradient direction to ensure that the three term-memory gradient projection direction is a descent direction. A new three term-memory gradient projection method for nonlinear programming with nonlinear equality and in-equality constraints is presented.

利用广义投影矩阵，对求解无约束规划的三项记忆梯度算法中的参数给一条件，确定它们的取值范围，以保证得到目标函数的三项记忆梯度广义投影下降方向，建立了求解非线性等式和不等式约束优化问题的三项记忆梯度广义投影算法，并证明了算法的收敛性。

Criteria for model comparison were residual variance estimates, minus two log likelihood function, Akaike's information criterion, Bayesian information criterion, Bayesian factor, information-theoretic measure of model complexity, and percent relative reduction of complexity.

模型的统计标准有总剩余方差、似然函数对数值、Akaike信息尺度、贝叶斯信息准则、贝叶斯因子、模型复杂性尺度和复杂性相对下降率。

An experiment of 16 channels sequency division mult plex system has bsen completed by the RF earner channel for the transmission of telemetry signals.

本文介绍一个在一般遥测用射频信道上实现16路沃尔什复用系统的实验。沃尔什函数作为付载波经带限信道后其波形要产生上升、下降沿，这将导致各路间的正交误差。

Fault condition includes the descent of cable force, sinkage of bridge tower and structure change of the main girder. Data recorded are cable force, girder stress, girder linetype, frequency response function, mode shape and etc.

其中损伤的形式有索力下降、主梁局部刚度变化以及桥塔不均匀沉降等，监测的参数主要有拉索索力、桥面线型、主梁应变等静态参数以及主梁固有频率、频响函数和振型等动态参数。

The mixed method raise the convergent rate of the conjugate gradient method, and solve the problem which the steepest descent method can not solve in the condition with badly characteristics for the objective function.

混合算法既提高了共轭梯度算法的收敛速度，又解决了目标函数"性态不优"时，最速下降法难以求解的问题。

The content of tissue water can reflect status of growth. The tissue water got its greatest content in the animal bodies at 25℃. Tissue water decreased as a function of salinity.(6)The isosmotic point for subadult Macrobrachium nipponense is about 14‰, the optimum temperature for its growth is around 25℃.

5组织水含量可反映出机体生长状况，本实验25℃各盐度实验组动物体内组织水含量最高；不同温度下组织水含量的下降都是盐度的函数。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。