考虑道路形状约束的车辆轨迹聚类方法

随着车联网技术的不断发展,产生了海量车辆轨迹数据。这些车辆轨迹数据可以通过聚类分析方法挖掘出车辆行驶的潜在规律,从而实现指导车辆出行的目的。提出一种基于密度的车辆轨迹聚类方法,对基于道路形状关键点位置选取的车辆轨迹信息进行重构,并考虑车辆在路网中移动的空间约束,分析聚类结果得到城市道路的交通状况,以此指导车辆出行以避免或减轻车辆拥堵。基于福州市真实的车辆数据对提出的车辆轨迹聚类算法进行验证,并对最后的聚类结果进行了详细的分析。实验结果表明,针对车辆轨迹聚类并结合道路网络的方法能够更加真实反映车辆的行为特征。     

基于模糊关联规则与减法聚类的神经模糊建模

针对许多复杂系统的输入变量之间存在的相互关联,提出了一种基于聚类与模糊关联规则的神经模糊建模方法.这种方法采用基于聚类的模糊关联规则挖掘算法来进行输入变量的选择,之后,再采用基于减法聚类的神经模糊建模方法建模.最后,还将这种建模方法应用于实际建模问题,结果表明这种方法在保证模型精度符合建模要求的情况下,减少了模型输入个数,降低了建模的复杂程度.     

基于设计结构矩阵的船舶MDO建模

为了降低船舶多学科设计优化(MDO)模型的耦合度,从而间接提高优化效率,以一种基于联系信息流量的聚类算法为基础,提出了一种重组模型的建模技术.对聚类算法的基本假设和计算方法进行了改进,用指数函数取代了线性函数,并完善了编码.提出了针对聚类方案的评价指标——联系权重在聚类内部的百分比和BUS聚类规模,用于比较改进效果.最后以5400箱集装箱船方案设计初期的概念建模为例说明了基于改进聚类算法的建模技术,验证了该技术用于船舶建模的可行性.     

一种基于T-S模糊模型的自适应建模方法及其应用

提出了一种改进的基于T-S模糊RBF神经网络模型的辨识算法和自适应方法,采用模糊C均值聚类(FCM)算法划分输入输出数据空间,最后将该算法应用于丙烯腈收率的预报,仿真结果表明了这种基于T-S模糊模型的自适应建模方法的有效性。     

基于聚类和文化算法的补偿模糊神经网络建模方法

根据补偿模糊神经网络的建模特点,提出了基于聚类和文化算法的补偿模糊神经网络建模方法。该网络的学习分为两步:结构辨识和参数辨识。在结构辨识中,采用改进的聚类算法确定模糊规则数及初始参数,构造一个初始模糊模型;在参数辨识中,采用基于多层信念空间的文化算法对具有5层结构的补偿模糊神经网络参数进一步优化,使其具有更高的精度。通过对TE过程的故障诊断建模,结果表明该网络在建模精度和收敛速度上均优于常规补偿模糊神经网络和常规模糊神经网络。     

模糊K-m eans算法在临床路径决策中的应用

针对临床路径决策分析聚类算法中聚类效果依赖于样本数据分布且处理数据效率低的问题,提出基于均衡分配方法的模糊K-means算法的临床路径决策方法.该算法利用文字数字化处理与加权计算来建立数据格式统一且关键属性突出的样本特征值矩阵;利用基于均衡分配方法的模糊K-means算法对上述样本进行聚类分析,得到最终的聚类中心与聚类结果,以此辅助医生进行临床路径决策.采用ECLIPSE编程进行仿真,与传统模糊K-means算法和基于减法聚类的FCM算法相比,采用该算法的迭代时间分别降低了26%与70%,迭代次数分别减少了33%和82%,平均目标函数最小值分别减小了32%和28%.实验表明,该算法能够有效降低聚类效果对于样本数据分布的依赖,同时数据聚类效率与质量也有显著的提高.     

基于目标函数的矩阵分解非线性系统模糊建模

提出了基于新的目标函数的模糊聚类建模方法．改进的模糊聚类方法把模糊模型结构辨识和参数辨识融为一体．首先,通过新的目标函数的最小化确定模糊模型的输入空间,即确定模糊规则和规则数、参数．然后对经模糊聚类得到的模糊前件推理矩阵进行QR分解,通过分析秩亏损确定重要的聚类规则．为了证明这种建模方法的性能,对非线性系统进行了仿真建模研究,仿真结果证明所提出方法是一种有效的、精确的模糊建模方法.     

基于粗糙集理论的岩体结构面模糊C均值聚类分析

基于在利用模糊C均值聚类算法对岩体结构面产状进行优势分组时,需要人为确定分组数和初始聚类中心,在迭代过程中容易陷入局部最优解的问题,通过改进聚类中心的算法,提出一种基于粗糙集的模糊C均值聚类算法,以优化迭代过程,并通过对比多项聚类有效性检验参数,确定最优聚类分组情况。最后采用模糊C均值聚类算法和改进后的算法对浙江白鹤隧道左洞测得的结构面产状进行优势分组并对比。计算结果表明,本文所提出的方法聚类效果明显优于模糊C均值聚类算法。     

智能车辆轨迹跟踪控制方法研究

针对智能车辆的轨迹跟踪控制问题,提出了一种可以调节参数的智能车辆轨迹跟踪控制方法.首先,设计了模糊控制器对智能车辆进行路径跟踪控制;其次,为了提高车辆在高速下的路径跟踪效果,设计模型预测控制器,并结合轮胎的动力学特性及车辆动态特性对轮胎侧偏角、质心侧偏角等进行约束;然后,为了提高车辆在不同工况下的路径跟踪效果,进一步设计了基于PSO算法的模型预测控制器.比较三种控制器的控制效果,选择典型工况在联合仿真平台上进行仿真.结果表明,提出的智能车辆的轨迹跟踪控制方法可以有效地对车辆轨迹进行跟踪.     

一种改进的T-S模糊模型建模及优化方法

模糊建模是一种有效的非线性系统建模方法,因为非线性系统的复杂性,仍有很多问题难以处理。针对T-S模糊模型,提出了一种改进的建模及优化方法。首先,将快速搜索密度峰聚类和模糊C均值聚类(FCM)算法相结合,使用快速搜索密度峰聚类算法找到聚类个数和初始聚类中心后,再用FCM算法进行聚类;然后,通过最小二乘法辨识结论参数得到初始T-S模糊模型,使用改进的差分进化(DE)算法整体优化模型的结构和参数,获得最终的T-S模型;最后,选择代表性实例,使用MATLAB程序进行仿真分析和比较,验证了本文方法能有效提高T-S模糊模型的辨识精度和速度。     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the