车用永磁同步电机定子模态分析

针对电动汽车运行过程中产生的振动噪声问题,以某车用永磁同步电机为研究对象,运用Ansys Maxwell软件分析电机气隙磁密,得到电机运行的气隙磁场和径向电磁力,再对永磁同步电机的定子进行模态分析,得到定子系统的固有频率,同时采用锤击法结合LMS软件进行模态试验,将有限元仿真和模态试验数据进行对比,验证有限元模态分析的准确性。结果表明,该永磁同步电机的定子结构模态频率和径向电磁力波频率有较大的差异,不会由于电机径向电磁力而产生共振,这项工作为解决电机振动噪声问题和优化汽车NVH性能提供了参考。     

汇改后中国外汇市场与资本市场联动效应——基于集合经验模态分解法

以投资者预期收益变动逻辑起点,构建在不同预期收益下外汇市场与资本市场的联动机制理论模型,进而将2005-2014年按金融市场改革历程划分为4个阶段,通过集合经验模态分解法对中国外汇市场与资本市场的数据进行分解,过滤掉代表资本价格随机波动的短周期分量,提取最具代表联动性的长周期趋势分量。采用VAR-GARCH-BEKK模型对4个阶段两个市场的均值溢出效应和波动溢出效应进行分析,结果显示:受中国经济增长的方式以及外汇管制制度影响,不同阶段两个市场间的溢出效应呈现出不同的特点,虽然总体来看联动强度有一定程度的加强,但是两个市场间"资金价格"传导机制的脆弱性并未获得实质性的改变。因此,只有推进汇率市场化,循序渐进的加快资本项目可兑换,完善人民币汇率形成机制,才能够不断提高货币政策调控的主动性和有效性性,维护国家利益。     

基于ANSYS的行李车改造成发电车的车架设计与分析

现代设计方法的发展和使用,使铁路车辆设计变得越来越快速高效。在行李车改造为发电车过程中,首先根据车架结构对车厢进行布局设计,其次运用有限元分析软件ANSYS对改造后的车辆车架系统从强度和刚度方面进行计算和分析。然后根据分析结果,使用APDL语言对车架薄弱环节和不合理结构进行改进。最后,对改造后车架进行模态分析和谐响应分析,确定有害频率和振型,并采取有效减振措施。从研究结果看,改造后的车辆车架能达到安全使用的设计目的。     

基于EMD的非线性信号自适应分析

根据EMD分解原理,提出通过选择平均包络中的突变点确定自适应滤波器截止分量阶,以此构造时空滤波器组进行非线性信号自适应分析的方法,成功应用于分析波音737飞机涡轮轴振动信号。从噪声中自适应地提取随转速变化的信号分量和低频振动分量,与小波分析方法相比,在轴向位移检测中取得了更为满意的效果。该方法不仅改进了涡轮轴振动信号分析方法,也适用于解决其他非线性信号的分析问题。     

考虑油膜结合面的机床动态特性分析

考虑油膜结合面特性的机床主运动板的动态特性分析,对油膜的刚度分布情况作了3种假设,将假设得到的机床动态特性与不考虑油膜的特性进行比较,并用实验测试数据进行验证正确性。结果表明考虑油膜即结合面的特性对模态分析结果产生不可忽略的影响,其影响效果从第5阶模态振型开始表现明显;油膜刚度成分布幂函数最接近实验测试结果,因此可以看做油膜工作状态下分布的简化函数。     

科学思维类组的语言结构形式探讨

文章对随机抽取的被试在两难问题处理语境中问题解决方案提出的语言结构形式进行分析,结果显示:模态词、陈述句和名词可以成为实现科学思维训练的操作性目标。     

模态系统T的Herbrand定理

模态Herbrand定理研究是模态逻辑领域的重要开放问题.不含Barcan公式的模态系统T的Herbrand定理的获得必须完成两个方向的证明工作:首先是证明相对简单的从右到左方向;而对于相对复杂的从左到右方向,则可以通过在加标公式表列系统K的基础上增加特殊规则获得加标公式表列系统T,证明T的可靠性和完全性,并在此基础上完成从左到右方向的证明.同样的方法还可以用来证明模态系统D、K4、s4的Herbrand定理.     

FEPA-金融时间序列自适应组合预测模型

本文报告一种金融时间序列预测的信号分析、信息融合与智能计算组合模型,简称FEPA,由针对金融时间序列（FTS）信号分析的经验模态分解（EMD）、用于数据降维的主成分分析（PCA）和用于非线性建模的人工神经网络（ANN）三部分组成。该模型首先应用滑动窗口截取原始金融时间序列最近期数据集,应用EMD分解算法把数据集分解成不同尺度的本征模态函数（IMF）,然后通过主成分分析将分解后的数据降维,提取最有信息量的特征;然后将这些特征输入到神经网络进行组合预测。本文提出的组合预测模型FEPA是基于分解-提优-合成的信息融合思想,有效提高了预测可靠性。其创新点在于：1）首次给出了EMD算法的结构化表达,提供了今后融合更多信息的算法接口;2）通过多步长预测输出深入研究EMD分解的有效信息结构;3）通过切换到更细时间框架来处理EMD的端点效应,并探索了两级时间框架下的预测效果;4）给出了金融时间序列组合预测模型的一般性架构,具有可升级性和可扩展性。并且通过滑动窗口EMD使得实证更能切近实际。通过在沪深300股指和澳大利亚股指上的实证,结果表明FEPA预测模型在沪深300股指日线和15分钟线上的预测命中率高达78%和82%,在澳大利亚股指日线上也达到了74%的命中率,经比较,明显高于文献中常见的5种模型。     

创新理念 推进自治制度运行和自治地方治理现代化

Deepening reform, promoting the rule of law, and implementing the “Five Develop￣ment ” concepts have had a deep influence on the modernization of governance in ethnic autonomous regions. Based on a review of 30 years of success￣ful experiences in implementing ethnic regional au￣tonomous law, and focusing on the concepts of“innovation, coordination, green development, openness and sharing”, we need to conduct in -depth research on the ways to:promote governance by law, realize the modernization of governance;and promote the efficient implementation of ethnic autonomous systems in the ethnic autonomous re￣gion.
The 155 ethnic autonomous areas of China cover 64% of the total area of the country. There￣fore, the governance of the country cannot be a￣chieved without modernizing the governance in the ethnic autonomous regions. Modernizing the gov￣ernance in ethnic autonomous regions is a necessa￣ry element for modernizing the governance of the nation. The modernization of the ethnic autono￣mous regions actually means the legalization of the governance in ethnic autonomous areas, which is a main part of the legalization of the ethnic affairs.
The comprehensive, deepening of reform, and promoting governance by law have been strongly promoted. We should start from reality, respect differences, and take the development concepts of“innovation, coordination, green, openness and sharing” into consideration so as to promote the ef￣ficient implementation of ethnic regional autono￣mous systems through various methods. We should update our concepts, weaken specificity, solidify locality, intensify new thinking, innovate the run￣ning of ethnic autonomous systems, and promote the modernization of governance in ethnic autono￣mous regions. Based on a comprehensive analysis of the theories and practices used since the imple￣mentation of ethnic regional autonomous regula￣tions, and under the premise of intensifying “the legalization of ethnic affairs”, we should deepen the comprehensive reform of the ethnic autonomous regions, comprehensively promote the governance by law, and realize the goal of building a moder￣ately prosperous society as scheduled through im￣proving and innovating the running of ethnic re￣gional autonomous systems.
“Ethnic areas are districts with rich resources and water sources; they are ecological screen zones, cultural characteristic zones, border areas, and poor areas.” At the same time, due to histori￣cal, social and natural factors,“the natural condi￣tions of most ethnic areas are not good; their be￣ginning phase of development is low; they have many historical debts; they are located far away from the central markets and urban areas;their ur￣ban-rural gap is very obvious”, and “their gap with the eastern areas ( of China) is growing larger and larger”. The reform and the promotion of gov￣ernance by law in ethnic autonomous areas should put more emphasis on locality, ethnicity and “au￣tonomy”. Of course, we must avoid of “artificial￣ly” intensifying ethnic consciousness, and creating ethnic “differences”. Meanwhile, we should “im￣prove the capability for legal management of ethnic affairs”, “intensify the construction of laws and regulations related to ethnic work”, “legally han￣dle those issues involving ethnic factors”, “insist on resolving issues involving ethnic factors by the law, and avoid of regarding civil and criminal problems related to ethnic people as ethnic prob￣lems, or regarding common disputes in ethnic are￣as as ethnic problems. ”
We should affirm that China’s ethnic relations are harmonious, and that their economics are de￣veloping rapidly. Since the implementation of the policy of “reform and opening -up”, especially since 2005 , the economics in ethnic autonomous regions have developed dramatically; the people’s living conditions have continuously improved;bas￣ic infrastructure has significantly speeded up; and ecological protection has solidly improved. Howev￣er, the problems still prevail. For example, the poverty in ethnic areas is still serious—there are more than 25 million poor in ethnic rural areas. Therefore, the task of poverty alleviation is still very tough. In addition, the gap between urban and rural areas and between different regions is very large in ethnic autonomous regions. Finally, the rate of urbanization is very low.
In sum, during the process of modernizing so￣cial governance in ethnic autonomous regions, we must pay full attention to the five“stage character￣istics” of ethnic work in China which are the:( i) co - existence of opportunities and challenges brought by the “reform and opening -up” policy and the socialist market economy;( ii) co-exist￣ence of the state’s constant support to the ethnic ar￣eas and its low level of development; ( iii ) co -existence of the state’s constant support to the eth￣nic areas and the weak level of basic public service capability in ethnic areas; ( iv ) co -existence of the constant exchange and fusion between various ethnic groups and the disputes involving ethnic fac￣tors;and ( v) co-existence of the great achieve￣ments in anti-national splittism, religious extrem￣ity, and violent terrorism, as well as the active ter￣rorism activities in some areas. Only when we rec￣ognize this situation, can we understand the speci￣ficity of doing ethnic work in China. The innova￣tion of governance of ethnic autonomous areas and the promotion of governance by law in the whole country must start from this actual situation.
At present, we still need to clarify the conno￣tations of autonomous rights. Based on a clear clar￣ification of the basic meaning of ethnic regional au￣tonomous rights, we should deepen reform, active￣ly transform the governance of the ethnic autono￣mous regions, further deepen relevant theoretical studies, and positively promote the ethnic regional autonomous system. The main purpose of the eth￣nic regional autonomous areas is to promote the de￣velopment of the various affairs of ethnic minorities and ethnic regional autonomous areas. The purpose for improving the ethnic regional autonomous sys￣tem is to ensure the development of ethnic minori￣ties and ethnic regional autonomous regions. Im￣proving the ethnic regional autonomous system should transform from one of preferential treatment to one of nuanced development.
Looking back to the past, the legal construc￣tion of ethnic regional autonomy has made great a￣chievements. However, the preferential policies of the state and relevant institutes are still the real factors promoting the development of the various af￣fairs of the ethnic minorities and ethnic autonomous areas. As described in this article, there are multi￣ple factors which influence the efficiency and per￣formance of the ethnic regional autonomy. The eth￣nic autonomous regions are restricted by natural conditions and economic development, therefore, they have to depend on assistance from the state and the relevant institutes—this is the objective re￣ality. However, the improvement of the ethnic re￣gional autonomous system must change the status of the past, and enable the ethnic regional autono￣mous system play out its actual role so that the va￣rious affairs of ethnic minorities and ethnic autono￣mous regions can step onto a road of nuanced de￣velopment.
The future development of the ethnic regional autonomous system depends on the consensus of theoretical and practical circles, i. e. a long-term mechanism whose purpose is to enable the system itself play its actual role should be established. Only by such a mechanism, can these puzzling problems be solved and gradually improved. Tak￣ing the breakthrough of the actual effect of the sys￣tem as the starting point of the ethnic regional autonomy’s deepening of the reform, one should take the following aspects into consideration:1 ) re-examine existing laws and regulations, and im￣prove them on the basis of institutional norms, en￣hance normalization, uniformity and manipulability of the ethnic regional autonomous regulations; 2 ) sort out the relationship between the institutions in ethnic autonomous areas and the upper levels of the state institutes, as well as the relationship be￣tween the institutions on the same level;on the va￣rious institutional levels, enhance clear cognition on the position, role and organizing principles of the ethnic regional autonomous system, and avoid taking the ethnic regional autonomous system as the affairs of the ethnic autonomous areas;3 ) im￣prove the supervisory mechanisms for running the ethnic regional autonomous system; and 4 ) im￣prove the mechanisms for handling disputes on the running of the ethnic regional autonomous system.
We must work closely, share the achieve￣ments, and promote the operation of the ethnic re￣gional autonomous system. For this purpose, we should:1 ) standardize the management of the eth￣nic regional autonomous system, and weaken the“specificity”;2 ) promote the governance capabili￣ty of the ethnic regional autonomous areas, and so￣lidify the concept of“locality”;3 ) enhance auton￣omous awareness and capability, intensify “new thinking”, motivate initiatives from the autonomous areas, and improve the autonomous system from the bottom-up, and rationally allocate the power and rights of the high-level organs and the auton￣omous organs in the ethnic autonomous areas.     

基于EMD与DVG的非线性时间序列预测模型及其应用研究

针对具有非线性和不稳定性的时间序列,提出一种结合经验模态分解(EMD)、有向可见图(DVG)网络的动态预测模型。利用经验模态分解将原时间序列分解为多个固有模态函数(IMF),然后对分解后的高频和低频IMF利用快速傅里叶变换得到各自的周期;依据每个周期,从原时间序列的尾部截取长短不一的子序列,然后采用有向可见图算法转换为多个有向网络,利用随机游走在每个有向网络中寻找与时间序列最后一个节点相似的节点;最后,依据平行线法,预测时间序列的下一个数值。原油价格的时间序列是一类典型的具有非线性和不稳定性的序列,利用此模型对WTI原油每日价格进行实证分析。研究结果表明,此模型不但可以有效地预测时间序列的变化趋势,而且具有较高的预测精度。