空调对象参数辨识的一种混合算法0

针对空调对象这一时变迟延环节,提出了一种基于最速下降法和最小二乘法的混合参数辨识算法．对一空调对象分别在初始条件未知和参数发生突变的前提条件下进行了参数辨识．计算结果表明,提出的混合参数辨识算法不但适用于时不变的空调系统,而且对时变的空调系统也具有辨识性能稳定、计算时间少、计算精度高等优点．     

惯性特征系统最速特征模型PID控制参数辨识

以惯性特征系统作为研究对象,针对常规PID控制器参数的设置问题提出了基于系统最速特征模型的辨识算法,该算法利用惯性特征系统的输入输出特性,通过最小二乘法辨识出系统的一阶特征模型,然后再根据一阶特征模型、控制律和系统的动、稳态性能的要求辨识出系统的二阶最速特征模型,同时也计算出PID控制器的参数.仿真结果表明,该算法能够使PID控制具有最速响应的特征,为PID参数设置提供了一种计算方法.     

直线滚动导轨结合部动力学特性测试及参数识别

基于辨识原理,提出了导轨结合部动力学参数的试验辨识流程,包括标记测量点、频响函数测试、测试数据处理、编制辨识程序等步骤.以组装在床身上的THK导轨结合部为对象,进行了动力学特性测试.并应用Matlab编制了辨识算法,识别出导轨结合部系统法向方向的质量矩阵、刚度矩阵、黏性阻尼矩阵和结构阻尼矩阵,证明了动刚度矩阵法辨识导轨结合部动力学参数的有效性.     

大型同步发电机参数在线辨识系统校验与分析

为了评估参数辨识的准确性和由实测参数构成的数学模型对电力系统暂稳态计算的影响,针对已提出的动态在线辨识方法和得到的辨识参数结果,在东北通辽地区电网上进行了大规模系统校核试验和系统稳定计算分析。校核和分析结果表明：所得到的同步电机模型和参数符合实际系统,采用实测模型参数（包括励磁系统和调速系统）后,通辽电厂的发电机稳定极限可以提高５％左右。     

线性粘弹性弹支多转子系统参数辨识

提出了带线性粘弹性弹性支承的多转子系统物理参数辨识的一种方法。该方法把多转子系统看作复合结构,用动态子结构分析的阻抗匹配法进行动力学计算,用增广拉格朗日乘子法对系统特征方程的系数行列式作迭代计算,获得系统物理参数的辨识结果。该方法可以准确计入陀螺力矩的影响;避免测量振型参数;并利用系统的稀疏模态和小阻尼等特点简化了分析;还介绍了一种建立线性粘弹性弹支多转子系统动力学模型的方法。计算结果与实验结果吻合良好     

基于双层自适应遗传算法的机器人参数辨识

激励轨迹的选取和优化是机器人动力学参数辨识的重要基础。为了提高机器人动力学参数的辨识精度,以SCARA机器人为研究对象,设计了基于双层自适应遗传算法的机器人激励轨迹优化方案。运用Newton-Euler法建立了机器人的动力学模型,并对机器人的动力学模型进行线性分离,得到了机器人的最小惯性参数集和对应的观测矩阵。分析机器人的参数辨识方程,确定了观测矩阵条件数最小的优化目标。针对传统遗传算法进行改进,提出了双层自适应机制,提升了算法的全局搜索能力和搜索效率。最后利用MATLAB和ADAMS进行联合仿真实验,使用递推最小二乘法计算机器人的最小惯性参数集。实验结果表明,使用改进的双层自适应遗传算法得到的激励轨迹可以保证机器人动力学参数的辨识精度。     

有色噪声干扰系统的参数辨识递推算法

为了辨识受有色噪声干扰的系统参数,提出一种递推算法。该算法由系统部分的参数估计和噪声部分的参数估计2部分组成。系统参数估计采用的是包含当前预报误差和之前估计误差的递推算法辨识。噪声部分参数则是采用扩展的最小二乘算法辨识。该文对新的递推算法进行了仿真,实验结果显示该算法能够降低噪声对参数估计的影响,减小估计误差,较精确地辨识出受有色噪声干扰系统的参数。     

有色噪声干扰系统的参数辨识递推算法

为了辨识受有色噪声干扰的系统参数,提出一种递推算法。该算法由系统部分的参数估计和噪声部分的参数估计2部分组成。系统参数估计采用的是包含当前预报误差和之前估计误差的递推算法辨识。噪声部分参数则是采用扩展的最小二乘算法辨识。该文对新的递推算法进行了仿真,实验结果显示该算法能够降低噪声对参数估计的影响,减小估计误差,较精确地辨识出受有色噪声干扰系统的参数。     

尺度变换下的直流电机参数辨识方法与实验验证

针对传统参数辨识方法计算复杂且依赖过多测试数据的问题,提出一种基于尺度变换的直流电机参数辨识新方法.首先,建立具有驱动放大系数和响应时延的电机系统与一类标准化对象之间的频域/时域尺度变换关系.然后,分析标准化对象的阶跃响应特征与主导参数的作用,结合主导参数定义,拟合反映阶跃响应特征的函数.最后,基于尺度变换与特征函数,给出电机模型参数的直接计算方法和优化计算方法.仿真和实验结果表明:文中所提方法具有正确性和有效性.     

大型立式淬火炉温度分布参数系统参数辨识算法

以块脉冲函数为基函数,利用正交函数变换将由偏微分方程描述的分布参数系统模型转化为最小二乘形式的代数方程,在此基础上推导出大型立式淬火炉温度分布参数系统的参数辨识算法,并进行仿真和31m立式淬火炉温度控制系统应用,该算法能够满足控制规律对参数辨识实时性和精度的要求。研究结果表明：基于正交函数逼近法的分布参数系统参数辨识算法的关键在于正交函数正、反向积分运算矩阵的求解。辨识过程中考虑大型立式淬火炉温度分布参数系统模型边界条件和初始条件的影响,提高参数辨识精度,参数辨识精度为-6％～6％,保持系统的空间分布特性,算法计算量小,可以实现在线参数辨识。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that