北魏孝文帝迁都洛阳原因补论

向南迁徙是拓跋鲜卑的历史传统。孝文帝舍平城而选洛阳作为都城,乃为实现其政治理想。孝文帝的正统思想和大一统理想体现了迁都洛阳的必然性,其后进行的风俗改革则彰显了迁都洛阳的必要性。从东晋迁都洛阳之争来看,洛阳是统一帝国的都城首选。孝文帝迁都洛阳正是看中了洛阳的政治象征意义和文化价值。     

基于移动平均模型对上海未来空气质量的定量评估

对2010年上海世博会相关重大事件活动效应进行估算有着十分重大的现实意义,其中部分问题的提出及解决方案对现实中的环境保护起着指导作用.以时间序列预测法的移动平均模型为依据,在对其进行改造的基础上,用通行的Excel程序包进行统计分析,实现了对世博会环境效应的定量评估.     

基于求解TSP问题的双向扩展差额算法

旅行商(TSP)问题是典型的组合优化中的NP-hard难题.本文在最近城市搜索法和两端延伸最近城市搜索法基础上提出了双向扩展差额求解算法,并分析了算法的复杂度.采用以上三种算法求解了TSPLIB标准库中多个算例,比较结果表明本算法能够更快的找到更优的方案,具有更好的综合性能.     

需求预测综合模型及其与库存决策的集成研究

准确的预测有助于企业做出有效的决策,包括生产计划、定价和促销决策等,以减少库存、提高客户满意度和企业竞争力． 以快速消费品为研究对象,分析其需求影响因素,建立了时间序列分析与多元回归整合的需求预测综合模型; 将此预测模型引入到库存决策中,构建了基于库存成本最小的需求预测与库存决策集成模型,并借助变邻域搜索算法获得模型的参数值; 最后,选用实际数据,验证了所构建的需求预测综合模型、物流需求预测与库存决策集成模型及其求解方法的有效性．     

Writing organization/romancing fictocriticism

A provocation?…?the minds of my generation of organizational theorists are haunted by the spectre of scientific discourse, shoehorned into dry genres, bullied by audit regimes that try to wring the passion out of thought. Without gaiety, the science that calls us has no exuberance, it cannot dance. What are the possibilities for writing about organizations that allows the heart's instincts to be followed, the vast possibilities of expression to be explored and enjoyed? I explore this through a form of writing known as fictocriticism – a writing engaged in genre-bending as a literary and theoretical engagement with existence and selfhood. Why import this term into organization studies? Might fictocriticism have some value to ‘us’ who locate ourselves here? I am engaging in a form of romance; a courtship of ideas from elsewhere. What might result from this union is not clear, but it offers hope, excitement and promise.     

Phase-II monitoring and diagnosing of multivariate categorical processes using generalized linear test-based control charts

In this paper, two control charts based on the generalized linear test (GLT) and contingency table are proposed for Phase-II monitoring of multivariate categorical processes. The performances of the proposed methods are compared with the exponentially weighted moving average-generalized likelihood ratio test (EWMA-GLRT) control chart proposed in the literature. The results show the better performance of the proposed control charts under moderate and large shifts. Moreover, a new scheme is proposed to identify the parameter responsible for an out-of-control signal. The performance of the proposed diagnosing procedure is evaluated through some simulation experiments.     

Effect of systematic sampling on arima models

Given a general homogeneous non-stationary autoregressive integrated moving average process ARIMA(p,d,q), the corresponding model for the subseries obtained by a systematic sampling is derived. The article then shows that the sampled subseries approaches approximately to an integrated moving average process IMA(d,l), l≤(d-l), regardless of the autoregressive and moving average structures in the original series. In particular, the sampled subseries from an ARIMA (p,l,q) process approaches approximately to a simple random walk model.     

Partial and inverse autocorrelations in portmanteau-type tests for time series

We present a decomposition of the correlation coefficient between x_t and x_t?k into three terms that include the partial and inverse autocorrelations. The first term accounts for the portion of the autocorrelation that is explained by the inner variables {x_t?1 , x_t?2 , …, x _{t? k+1}}, the second one measures the portion explained by the outer variables {x _t+1, x _t+2, } ∪ {x _t?k?1, x _t?k?2,…} and the third term measures the correlation between x _t and x_t?k given all other variables. These terms, squared and summed, can form the basis of three portmanteau-type tests that are able to detect both deviation from white noise and lack of fit of an entertained model. Quantiles of their asymptotic sample distributions are complicated to derive at an adequate level of accuracy, so they are approximated using the Monte Carlo method. A simulation experiment is carried out to investigate significance levels and power of each test, and compare them to the portmanteau test.     

移动最小二乘微分求积法解Helmholtz方程

用一种新型的数值方法--移动最小二乘微分求积法（MLSDQ）求解二维Helmholtz方程。MLSDQ方法是一种直接将微分方程离散的方法，它是将未知函数的各阶偏导数在离散点处的值用域内各配点的函数值加权组合来表示，权系数则直接用移动最小二乘Galerkin法中的形函数求导得到，通过MLSDQ技术将Helmholtz方程和相应的边界条件转化成为一组关于各配点位势的线性代数方程组，求解这组代数方程，便可得到各配点的位势，通过求解几个具有精确解的算例，讨论了方法的收敛性和数值精度，结果表明：该方法较适合于求解小波数的Helmholtz方程,对高波数的方程，需要设置大量的域内配点才能有较好的数值结果。