二阶中立型差分方程的振动准则

考虑二阶中立型差分方程△[an△(xn+pnxg(n))]+f(n,xσ(n))=0,获得了上述方程振动的充分条件.     

Prediction and forecasting in linear models with measurement error

We consider measurement error models within the time series unobserved component framework. A variable of interest is observed with some measurement error and modelled as an unobserved component. The forecast and the prediction of this variable given the observed values is given by the Kalman filter and smoother along with their conditional variances. By expressing the forecasts and predictions as weighted averages of the observed values, we investigate the effect of estimation error in the measurement and observation noise variances. We also develop corrected standard errors for prediction and forecasting accounting for the fact that the measurement and observation error variances are estimated by the same sample that is used for forecasting and prediction purposes. We apply the theory to the Yellowstone grizzly bears and US index of production datasets.     

Frugal innovation for supply chain sustainability in SMEs: multi-method research design

Abstract

In this study, we attempt to establish the missing links between supply chain sustainability and frugal innovation. Our study motivations stem from two facets of the emerging markets: first, the institutional barriers and, second, the resource constraints. We argue that there is a synergy in the concepts of frugal innovation and sustainability in supply chains and there is a need to further explore this synergy. Furthermore, we claim that even in the wake of many success stories in the frugal innovative supply chain management practices from emerging markets such as India, there are very few, if any, attempts made to understand the implications of a sustainability oriented frugal innovations in the particular context. To address this gap, we develop a model to establish the linkage between sustainable supply chains and frugal innovations. Our proposed conceptual framework depicts the hierarchy and interlinks of the identified enablers in developing sustainability oriented frugal innovative capabilities in supply chains. Furthermore, we have empirically validated our theoretical framework using survey data. We observed that most of the interpretive links are supported. These findings extend the understanding of frugal innovation for supply chain sustainability using multi-method research design, while also providing theoretically guidance to managers in the development of frugal innovation capability to achieve sustainability in supply chain in resource constrained environment.     

Bayesian Analysis of an Unobserved-Component Time Series Model of GDP With Markov-Switching and Time-Varying Growths

We propose an unobserved-component time series model of gross domestic product that includes Markov switching as an unobserved component. In addition to a trend component, the model has two time-varying drift components. One drift represents the expected rate of growth during recession; the other drift represents the expected rate during expansion. Estimates indicate a substantial decline in the latter annual rate for the United States from 6.4% in 1950 to 3.6% by 1990. We have employed weak priors based on prewar data. The estimation makes use of the Gibbs sampler and the Metropolis algorithm.     

由基函数选择辅助线性算子的方法

本文研究了同伦分析方法中由基函数选择有效的辅助线性算子的方法，并将其应用到同伦分析方法中，求解了一个非线性偏微分方程边值问题，并且获得了收敛的级数解．结果表明此方法是有效的，也有利于同伦分析方法的进一步研究．     

常系数线性微分方程初值问题的算子解法

以算子作工具,给出了常系数线性微分方程(组)初值问题的一种解法.     

Book Reviews

Books reviewed:
Robert E., Kass and Paul W., Vos, Geometrical Foundations of Asymptotic Inference: Curved Exponential Families
G.S., Maddala and C.R., Rao, (eds) Handbook of Statistics 15: Robust Inference
Gregory C., Reinsel, Elements of Multivariate Time Series Analysis
Murray, Rosenblatt, Gaussian and Non-Gaussian Linear Time Series and Random Fields
William S., Mallios, The Analysis of Sports Forecasting: Modeling Parallels Between Sports Gambling and Financial Markets
Alain, Desrosières, The Politics of Large Numbers — A History of Statistical Reasoning
Mahmut, Parlar, Interactive Operations Research with MAPLE Methods and Models     

子矩阵约束下矩阵方程XA=B的对称非负定解

利用矩阵的广义逆及奇异值分解 ,给出了子矩阵约束下线性矩阵方程XA =B有对称非负定解的充分必要条件 ,并在有解时 ,给出了相应解的一般表达式     

电波传播附加时延修正的软件实现

给出并用C语言实现了一种基于观测的大范围电波传播附加时延的修正方法 ,这对具有授时、定位等功能的无线电工程系统具有重要的意义     

广义KDV-MKDV方程的精确解

利用直接积分方法将广义KDV-MKDV方程化为一阶变系数非线性常微分方程组,然后用待定系数法确定相应的常数获得了广义KDV-MKDV方程新的精确解;利用先作假设变换后选取试探函数的方法来直接构造广义KDV-MKDV方程新的精确解.