查询词典 perturbed system

And an iterative sliding mode-PID control method is presented for a class of nonlinear perturbed system, in which the sliding mode VSC method is iteratively applied based on system output feedback.

该方法通过对系统输出迭代设计线性滑模函数，并引入传统PID控制，综合了滑模变结构控制与PID控制的鲁棒性强的特点，避免了传统PID控制积分引起的超调以及变结构控制的抖振问题。

Given this assumption, even if the parameters of the system are randomly perturbed, by either genetic mutation, environmental variance or experimental manipulation during development, the system will generate a limited and discrete subset of phenotypes.

而在这种假设的前提下，即使系统各参数值在发育过程中受到随机的扰动（或者是遗传突变，或者是环境变化或人工实验操纵），系统也会产生出某个有限的、离散的表型[11]子集。

The exact invariants of the symmetry for the system without perturbation are given. Perturbation to weakly Noether symmetry is discussed and the adiabatic invariants of the perturbed system are obtained.

给出了未受扰动系统的弱Noether对称性导致的精确不变量，讨论了受扰动后系统弱Noether对称性的摄动，并得到受扰动后系统的绝热不变量。

After the completion of DAE with removal of singular points, a DAE system may be transformed into ordinary differential equations on manifolds; it is also possible to transform DAE to a singular perturbed system as ODE.

通过将DAE完备化并去掉奇异部分，可以把DAE化为流形上的常微系统；也可以将DAE化为奇异摄动系统而得到ODE。

As a high-order, multivariable, nonlinear system, inverted pendulum's characteristic value distribution and the frequency range characteristic are similar to the singularly perturbed system's characteristic.

倒立摆作为一典型的高阶次、多变量、非线性系统，其特征值分布及频域特性非常类似于奇异摄动系统特点。

Comparing with existing solutions, new method can utilize generators' speed signal measured by wide area measurement systems directly and detailed model and parameter of power system components were not needed. After sphering measurement-data, ICA with maximal negentropy criterion was carried out to obtain feature matrix. By this means high-dimension data of multi-machine perturbed trajectories were reduced to lower dimensions, and coherent generator groups were identified by pattern recognition consequently. Simulation results of 36-bus system with 8-generator and planning northwest China 750 kV power grid show that noise signals and bad data can be eliminated. This method is accurate in identifying coherent generator groups.

与现有方法相比，这种方法不需要获得系统元件模型和参数，而是直接球化广域测量系统(wide area measurement systems，WAMS)提供的发电机电角速度信号，再利用最大负熵准则进行独立分量分析得到特征矩阵，将高维数的多机受扰轨迹数据变换到低维空间，通过模式识别得到分群结果。8机36节点系统和西北750 kV电网规划系统算例表明，该方法能有效消除噪音和坏数据的影响，准确识别出同调机群。

The following exciting results are revealed: 1 When considering the influence of some nonlinear elements such as hard-limit of exciters, the effects of some devices such as Power System Stabilizer and Static Var Compensator which can introduce positive damping in power system, the reasonability of system parameter values in simulation, the SNB surface and HB surface on the boundary of SSSR will turn close to each other and even coalesce together; 2 Under some conditions, coupling between slow exciters and shunt capacitors will bring negative damping in power system dynamics, which increases the possibility of oscillatory instability. So the power system with mass shunt compensators is easily subjected to the oscillatory instability. In recent years, chaotic phenomena of power system have been reported many times. Some simulation studies even found chaos existing inside the power system SSSR. In this dissertation, chaotic phenomena in power systems are thoroughly studied in order to make clear the relation of chaos and SSSR. The following results are derived: 1 Based on Li-Yorke Theorem and their definition on the chaos, the existence of chaos in power system is verified; 2 Three possible routes of causing chaos in power system are found and deeply investigated. They are route of cascading period doubling, route of directly initial energizing and route of torus bifurcation (or quasi-periodicity). The latter two routes are investigated for the first time in power system stability studies; 3 When the stability conditions of chaos are broken, it is found they can lead to voltage collapse, angle divergence, or voltage collapse with angle divergence simultaneously.

针对在电力系统小扰动稳定区域内可能存在混沌吸引域的有关报道，本文深入研究了电力系统混沌现象的出现途径和与系统失稳模式之间的关系：1利用Li-Yorke定理和Li-Yorke的混沌定义，从理论上证明了电力系统混沌现象的存在性；2发现了电力系统中导致混沌出现的三种可能途径：倍周期分岔导致混沌、初始能量直接激发混沌和经由环面分岔导致混沌，并对后两种新发现的途径进行了较为细致的研究；3发现了混沌极限环破裂导致电压崩溃、角度失稳以及电压崩溃和角度失稳同时出现的现象，其中混沌极限环破裂导致系统角度失稳和电压崩溃及角度失稳同时出现的现象均属首次报道；4证明由微分-代数方程描述的系统模型，其小扰动稳定域的边界只包含HB、SNB和SIB三种分岔界面，在SSSR的内部和边界上，均不可能存在会导致混沌的点，从而将混沌现象排除在小扰动稳定域的研究之外，简化了后者的研究工作。

Factory remaining hot water, remaining vapor and boiler heating system, were adopted in tilapia overwintering. Every step, such as site selection, pond and fish preparation, cultivation of fish, fish selection, timing of overwintering, stocking density and managements during overwintering, was compared among three systems. The results of data analysis showed that the survival rate in remaining hot water system was 12% higher than in remaining vapor system and 21.25% higher than in boiler heating system. The overwintering cost in remaining hot water system was 735 Yuan/m~3, which was 18 Yuan lower than in remaining vapor system and 71.4 Yuan lower than in boiler heating system. The profit in remaining hot water system was 201 Yuan/m~3, which was 162 Yuan higher than in remaining vapor system and 275.4 Yuan higher than in boiler heating system.

本论文采取了余热水、余热气、锅炉加温三种方式对进行罗非鱼越冬保种，从地点选择、越冬池、鱼的准备、越冬苗种的培育、越冬前催肥、越冬鱼的选留、越冬鱼进池时间和密度、越冬期间饲养管理等环节进行对比试验获得了三种方式的试验数据并进行了分析讨论，结果显示：余热水越冬雌亲鱼的成活率比余热气越冬高出12％、比锅炉加温越冬高出21.25％；余热水越冬雌亲鱼的成本每立方米为735元比余热气越冬的成本每立方米低18元、比锅炉加温越冬的成本每立方米低71.4元；余热水越冬雌亲鱼的利润每立方米为201元比余热气越冬的利润每立方米高162元、比锅炉加温越冬的利润每立方米高275.4元。

A class of nonlinear two species competition singularly perturbed initial-boundary-value problems in a reaction-diffusion system in biomathematics was studies using the modern method of differential equation.

利用微分方程的近代方法研究了生物数学中一类非线性两种群竞争模型的反应扩散系统奇摄动问题。

In this paper a two2point boundary value problem for a system of singularly perturbed ordinary differential problems is considered.

讨论奇摄动常微分方程系统的二点边界值问题，这是奇摄动问题中较难的部分。

Vishnu entered a dark fourth dimensional dream that did not support his field or continued life.

毗瑟挐进入了一个第四密度的黑暗梦想，那里并不支持他的能量场或继续生命。

Leaders and decision-making persons use it to collect the data, including the information of unit work, handing in fee, oweing fee, prepaying fee,changing and afterpaying and account transfering of joining-insurance employee, and account paying of all kinds of insurances from hospitalization insurance institutions.The collected data is picked up, organized, switched and showed to user.

该子系统主要面向各级领导、决策分析人员；从各个医疗保险经办机构和定点医疗机构采集数据，包括在各个医疗保险经办机构处理的单位办公信息，单位缴费、欠费、预缴费信息，参保职工变更信息，参保职工增减变动信息，参保职工补缴信息，参保职工帐户划拨信息：包括各定点医疗机构处理的各险种帐户支出信息，各险种的统筹金支付信息等；将采集的数据提取，组织和转换，然后展示给用户。