塑窗组装与安装的管理

塑窗组装与安装的管理是塑窗厂的一项重要工作，章对塑窗组装与安装的管理环节，应采取哪些控制和协调进行了分析，提出了加强这些管理的措施。     

The adequacy of asymptotic approximations in the near-integrated autoregressive model with dependent errors

We consider the normalized least squares estimator of the parameter in a nearly integrated first-order autoregressive model with dependent errors. In a first step we consider its asymptotic distribution as well as asymptotic expansion up to order O_p(T⁻¹). We derive a limiting moment generating function which enables us to calculate various distributional quantities by numerical integration. A simulation study is performed to assess the adequacy of the asymptotic distribution when the errors are correlated. We focus our attention on two leading cases: MA(1) errors and AR(1) errors. The asymptotic approximations are shown to be inadequate as the MA root gets close to −1 and as the AR root approaches either −1 or 1. Our theoretical analysis helps to explain and understand the simulation results of Schwert (1989) and DeJong, Nankervis, Savin, and Whiteman (1992) concerning the size and power of Phillips and Perron's (1988) unit root test. A companion paper, Nabeya and Perron (1994), presents alternative asymptotic frameworks in the cases where the usual asymptotic distribution fails to provide an adequate approximation to the finite-sample distribution.     

当代艺术审美理想的迷失与重建

中国当代艺术审美理想的迷失从根子上说是有些中国作家和艺术家社会背叛的结果,从美学上说,不但是席勒当年所批判的恶劣倾向的沉渣泛起,而且消解了人对自己的尊严的捍卫和对自由的追求。中国当代艺术审美理想的重建就是要求中国作家和艺术家精神寻根,按照美的规律创造。     

矿渣微粉和磨细粉煤灰双掺混凝土的试验与应用

讨论了矿渣微粉和磨细粉煤灰双掺(简称FS双掺)在大体积混凝土以及高强混凝土中的试验与应用,以此体现了它们在经济上的显著效应。     

协整在产业组织学中的应用

首先从协整的原理着手,结合产业组织学学科特点,分析了协整在产业组织学中的可用性。随后利用协整理论分析了LydiaPinkam公司的数据,给出了一个产业组织命题的经验证据,用实例说明将协整应用于产业组织学领域是一种有益的尝试。     

Nonlinear IV unit root tests in panels with cross-sectional dependency

We propose a unit root test for panels with cross-sectional dependency. We allow general dependency structure among the innovations that generate data for each of the cross-sectional units. Each unit may have different sample size, and therefore unbalanced panels are also permitted in our framework. Yet, the test is asymptotically normal, and does not require any tabulation of the critical values. Our test is based on nonlinear IV estimation of the usual augmented Dickey–Fuller type regression for each cross-sectional unit, using as instruments nonlinear transformations of the lagged levels. The actual test statistic is simply defined as a standardized sum of individual IV t-ratios. We show in the paper that such a standardized sum of individual IV t-ratios has limit normal distribution as long as the panels have large individual time series observations and are asymptotically balanced in a very weak sense. We may have the number of cross-sectional units arbitrarily small or large. In particular, the usual sequential asymptotics, upon which most of the available asymptotic theories for panel unit root models heavily rely, are not required. Finite sample performance of our test is examined via a set of simulations, and compared with those of other commonly used panel unit root tests. Our test generally performs better than the existing tests in terms of both finite sample sizes and powers. We apply our nonlinear IV method to test for the purchasing power parity hypothesis in panels.     

Testing for unit roots in time series models with non-stationary volatility

Many of the key macro-economic and financial variables in developed economies are characterized by permanent volatility shifts. It is known that conventional unit root tests are potentially unreliable in the presence of such behaviour, depending on a particular function (the variance profile) of the underlying volatility process. Somewhat surprisingly then, very little work has been undertaken to develop unit root tests which are robust to the presence of permanent volatility shifts. In this paper we fill this gap in the literature by proposing tests which are valid in the presence of a quite general class of permanent variance changes which includes single and multiple (abrupt and smooth-transition) volatility change processes as special cases. Our solution uses numerical methods to simulate the asymptotic null distribution of the statistics based on a consistent estimate of the variance profile which we also develop. The practitioner is not required to specify a parametric model for volatility. An empirical illustration using producer price inflation series from the Stock–Watson database is reported.     

市场分割下中国加工贸易出口主体分化问题研究

外部采购与加工贸易是近年来出现的新贸易现象,对中国来说,低廉的劳动力成本是取得加工贸易比较优势的主要原因,加工贸易发展进程中出口主体的分化是中国从城乡二元劳动力市场向城市二元劳动力市场转变的结果,要继续保持加工贸易比较优势,就应该增强劳动力市场的流动性,实现劳动力市场的统一。     

改革以来中国农村发展地区差距分析

本文在扩展农业部门新古典经济增长模型的基础上,构建了基于农业生产率指数和农村地区劳动力就业结构的农村发展指标,以此来衡量农村发展水平及其变化状况.为了考察中国农村发展地区差距的变化趋势,我们采用面板数据单位根检验的不同方法对其收敛性进行了严格的计量检验.检验结果显示,在考虑了时间和省份特殊效应、序列相关等因素的影响后,中国各省农村发展差距以及东中西部地区农村发展的内部差距均存在条件性β收敛.     

人参细胞工程研究概况

本文就人参细胞工程方面，对前人所做的工作和取得的成就进行了分类和综述，为人参细胞工程的进一步研究提供了一定的理论参考。