企业计算机库存控制系统设计

库存控制系统是企业管理信息系统中的重要子系统，与企业的生产工艺、生产组织和管理方式有着密切的关系，是衡量企业管理水平高低的重要标志，本文讨论了企业计算机库存控制系统的方式与程序设计问题。     

物流一体化过程中流程的重组与设计分析

随着经济的发展,物流产业作为用高新技术改造和整合传统产业而形成的新兴产业,正在全球范围内迅猛发展,被人称为降低物料消耗、提高劳动生产率之外的“第三种利润源泉”。一些物流理论迅速发展,物流一体化自从被提出后,受到了越来越多的关注。本文通过物流流程的分析,提出了物流流程的重组改造的途径,并就企业如何实现物流一体化进而实现供应链管理提出了自己的观点。     

工件加工工序的自由度分析

文章阐述了一种在机械加工中,为保证工件加工精度,对工件加工工序的自由度判定及分析的新方法。该方法简便,且提高了工件加工工序的自由度判定的准确性,具有实用性。     

谈储备土地的前期开发整理工作

土地整治与开发等一系列前期开发工作,是执行土地年度供应计划,有计划地将储备的土地重新投入市场的前提,是土地储备交易部门的重要工作,更是进一步提高土地价值和出让收益、实现＂净地＂招拍挂出让土地、减少不必要矛盾至关重要的环节。因此,必须严格遵守土地前期开发整理的程序和原则,并做好前期开发整理的资金筹措。     

生产和服务提供过程的确认及其控制

GB/T19001-2000《质量管理体系要求》中7.5.2"生产和服务提供过程的确认"是质量管理体系运行中控制难度大且极易出现问题的过程。本文结合实践,从识别需确认的生产和服务提供过程、开展生产和服务提供过程的确认活动及对确认后的过程实施控制等三个方面作出了阐述。     

Auditing Quality of Research in Social Sciences

A growing body of studies involves complex research processes facing many interpretations and iterations during the analyses. Complex research generally has an explorative in-depth qualitative nature. Because these studies rely less on standardized procedures of data gathering and analysis, it is often not clear how quality was insured or assured. However, one can not easily find techniques that are suitable for such complex research processes to assess the quality of the study. In this paper, we discuss and present a suitable validation procedure. We first discuss how ‘diagnosing’ quality involves three generic criteria. Next, we present findings of previous research in possible procedures to assure the quality of research in social sciences. We introduce the audit procedure designed by Halpern [(1983) Auditing Naturalistic Inquiries: The Development and Application of a Model. Unpublished doctoral dissertation, Indiana University] we found an appropriate starting point for a suitable procedure for quality judgment. Subsequently, we will present a redesign of the original procedure, with according guidelines for the researcher (the auditee) and for the evaluator of the quality of the study (the auditor). With that design, we aim to enable researchers to bring forward their explorative qualitative studies as stronger and more equally valuable to studies that can rely on standardized procedures.     

Simultaneous selection and weighting of moments in GMM using a trapezoidal kernel

This paper proposes a novel procedure to estimate linear models when the number of instruments is large. At the heart of such models is the need to balance the trade off between attaining asymptotic efficiency, which requires more instruments, and minimizing bias, which is adversely affected by the addition of instruments. Two questions are of central concern: (1) What is the optimal number of instruments to use? (2) Should the instruments receive different weights? This paper contains the following contributions toward resolving these issues. First, I propose a kernel weighted generalized method of moments (GMM) estimator that uses a trapezoidal kernel. This kernel turns out to be attractive to select and weight the number of moments. Second, I derive the higher order mean squared error of the kernel weighted GMM estimator and show that the trapezoidal kernel generates a lower asymptotic variance than regular kernels. Finally, Monte Carlo simulations show that in finite samples the kernel weighted GMM estimator performs on par with other estimators that choose optimal instruments and improves upon a GMM estimator that uses all instruments.     

Sequential point estimation of the powers of a normal scale parameter

We consider the sequential point estimation problem of the powers of a normal scale parameter σ^r with r≠ 0 when the loss function is squared error plus linear cost. It is shown that the regret due to using our fully sequential procedure in ignorance of σ is asymptotically minimized for estimating σ⁻². We also propose a bias-corrected procedure to reduce the risk and show that the larger the distance between r and −2 is, the more effective our bias-corrected procedure is. Received August 2000     

国内焊接工艺评定标准的对比及差异

目前,我国用于焊接工程的常用材料,其焊接性已基本掌握,要确保焊接质量,施焊前应进行焊接工艺评定,以评定施焊单位是否有能力焊出符合相应规程、规范和产品技术条件所要求的焊接接头。然而,国内不同行业的产品对其焊接工艺评定规定却不太一致,本文通过对国内常用的焊接工艺评定标准的对比,发现其不同点,因而在实际中应用时根据不同的要求选用不同的焊接工艺评定标准。     

Asymptotic second-order efficiency of three-stage procedure with a warranted confidence level

This paper considers a three-stage procedure which was proposed by Holm (1995) to yield a fixed-width confidence interval of the normal mean with a precise confidence level. The procedure is shown to be asymptotically second-order efficient. The procedure is also applied to such problems as bounded risk and hypothesis testing     

Solving Multicollinearity in the Process of Fitting Regression Model Using the Nested Estimate Procedure

In the practical cases, we are usually faced with the more difficult problem of multicollinearity in our fitted regression model. Multicollinearity will arise when there are approximate linear relationships between two or more independent variables. It may cause some serious problems in validation, interpretation, and analysis of the model, such as unstable estimates, unreasonable sing, high-standard errors, and so on. Although there are some methods to solve or avoid this problem, we will propose another alternative from the practical view in this paper, called nested estimate procedure. The first half of the paper explains the concept and process of this procedure, and the second half provides two examples to illustrate this procedure’s suitability and reliability.     

Simple Stepwise Tests of Hypotheses and Multiple Comparisons

Holm's (1979) step-down and Hochberg's (1988) step-up procedures for tests of multiple hypotheses are simple to apply and are widely used. Holm's procedure controls the familywise error rate (FWE), while Hochberg's is more powerful. This paper investigates a step-down procedure (labelled CS) of Seneta & Chen (1997) which is a sharpening of Holm's, takes into account the degree of association between test statistics, and also controls the FWE. Computation for the CS procedure may be minimized by using the procedure as an adjustment to Holm's. The computational steps are detailed, and the adjustment is then illustrated by an application to a text-book example of multiple comparisons, in which step-wise procedures are shown to perform better than the usual Tukey T -comparison. Simulation investigations in a standard comparison with a control setting show that the CS step–down procedure is more powerful than Hochberg's step-up procedure and the procedure of Simes (1986), especially in regard to error rate, and not much less powerful than an optimal, but very specific, step-up procedure of Dunnett & Tamhane (1992).     

存储过程在c/s数据库管理系统中的应用

通过对存储过程特性的分析,总结出存储过程的工作规律;通过实际的应用,得到了存储过程将提高数据库管理系统的效率和性能的结论并给出了应用存储过程的实例。     

基于云模型的动态物流过程知识表示

以提高物流过程管理实时优化调度的智能性和科学性为突破口,引入云模型和知识工程的知识表示理论,提出一种基于云模型的物流过程的知识表示法。通过云模型的期望值、熵和超熵三个数字特征有效地表达定性概念,并实现定性和定量的不确定转换,从而描述具有动态特点和一定非确定性的物流过程知识。     

INVARIANCE OF THE UNORDERED BEST ESTIMATOR IN THE T,–CLASS FOR MIDZUNO'S AND FOR IKEDA–SEN'S SAMPLING PROCEDURES

MIDZUNO'S sampling procedure is considered where the first (n – 1) draws are carried out with simple random sampling without replacement and the nth draw with varying probabilities. It is shown that for this scheme, the best estimator in the HORVITZ–THOMPSON (1952) T_t–class of linear estimators exists and rejects the last draw. When MURTHY'S technique of unordering of an ordered estimator is employed, the rejected draw is restored and the unordered estimator is obtained. Surprisingly, this unordered estimator is the same as the unordered best estimator in the T₁–class, derived for IKEDA–SEN'S sampling procedure.     

Partial parametric estimation for nonstationary nonlinear regressions

This paper proposes an estimation method for a partial parametric model with multiple integrated time series. Our estimation procedure is based on the decomposition of the nonparametric part of the regression function into homogeneous and integrable components. It consists of two steps: In the first step we parameterize and fit the homogeneous component of the nonparametric part by the nonlinear least squares with other parametric terms in the model, and use in the second step the standard kernel method to nonparametrically estimate the integrable component of the nonparametric part from the residuals in the first step. We establish consistency and obtain the asymptotic distribution of our estimator. A simulation shows that our estimator performs well in finite samples. For the empirical illustration, we estimate the money demand functions for the US and Japan using our model and methodology.     

A simple and effective scanning rule for a multi-channel system

We consider a multi-channel system in which one apparatus makes a sequence of observations, one at a time. By means of scanning, i.e. selecting a channel to be analyzed at any instant and deciding to stop at some stage, it is required to determine the channel in which there is the signal with prescribed constraints on error probabilities. A simple scanning rule, based on a cyclic application of a sequential probability ratio test (SPRT) is proposed for this problem. It is proved that in the case of Brownian motion, the expected scanning time of this rule is equal to the one of the optimal scanning rule (which is known only for this case). The simple structure of this rule permits to obtain corrected Brownian approximations for its characteristics in the case of exponential family of distributions. The same procedure is used in multi-channel change point problem.     

APP基于流程的精益生产研究与应用

针对APP在批次管理条件下,因产品品种烦多,生产批量少所造成的设备利用率不高、公司准时交货率较低、员工加班时数多等问题,提出基于流程的精益生产思想,在优化和规范企业生产流程的基础上,建立科学合理的组织结构及职能职责,同时建立细胞化生产系统,实施结果表明,该管理模式有效提高生产效率,降低产品生产周期。     

Statistical inference on restricted partial linear regression models with partial distortion measurement errors

We consider the estimation and hypothesis testing problems for the partial linear regression models when some variables are distorted with errors by some unknown functions of commonly observable confounding variable. The proposed estimation procedure is designed to accommodate undistorted as well as distorted variables. To test a hypothesis on the parametric components, a restricted least squares estimator is proposed under the null hypothesis. Asymptotic properties for the estimators are established. A test statistic based on the difference between the residual sums of squares under the null and alternative hypotheses is proposed, and we also obtain the asymptotic properties of the test statistic. A wild bootstrap procedure is proposed to calculate critical values. Simulation studies are conducted to demonstrate the performance of the proposed procedure, and a real example is analyzed for an illustration.     

Iterative Density Estimation from Contaminated Observations

We introduce an iterative procedure for estimating the unknown density of a random variable X from n independent copies of Y=X+ɛ, where ɛ is normally distributed measurement error independent of X. Mean integrated squared error convergence rates are studied over function classes arising from Fourier conditions. Minimax rates are derived for these classes. It is found that the sequence of estimators defined by the iterative procedure attains the optimal rates. In addition, it is shown that the sequence of estimators converges exponentially fast to an estimator within the class of deconvoluting kernel density estimators. The iterative scheme shows how, in practice, density estimation from indirect observations may be performed by simply correcting an appropriate ordinary density estimator. This allows to assess the effect that the perturbation due to contamination by ɛ has on the density to be estimated. We also suggest a method to select the smoothing parameter required by the iterative approach and, utilizing this method, perform a simulation study.