Developing and designing of an efficient variables sampling system based on the process capability index

Process capability indices (PCIs) are extensively used in the manufacturing industries in order to confirm whether the manufactured products meet their specifications or not. PCIs can be used to judge the process precision, process accuracy, and the process performance. So developing of sampling plans based on PCIs is inevitable and those plans will be very much useful for maintaining and improving the product quality in the manufacturing industries. In view of this, we propose a variables sampling system based on the process capability index C_pmk, which takes into account of process yield and process loss, when the quality characteristic under study will have double specification limits. The proposed sampling system will be effective in compliance testing. The advantages of this system over the existing sampling plans are also discussed. In order to determine the optimal parameters, tables are also constructed by formulating the problem as a nonlinear programming in which the average sample number is minimized by satisfying the producer and consumer risks.     

The Future of Statistical Computing on Desktop Computers

A class of computing devices known as desktop computers has emerged over the last several years. The International Data Corporation (McGovern 1980) estimates that the number of desktop computers is increasing by approximately 53,000 each month. Because of the projected widespread use of desktop computers and anticipated improvements in hardware, the potential for impressive statistical computing on these devices is exciting. Two features of desktop computers will be particularly important for those doing statistical analyses: (a) the ease-of-use of the computers, and (b) their extensive graphics capabilities. The author suggests that sophisticated statistical software will be available in the near future on many different models of desktop computers. Indeed, several of the manufacturers provide high-quality software at the present time. The implications for statisticians of a rapid growth rate for desktop computers are discussed for data analysis, software development, graphics, and instructional usage.     

A survey of low-cost,user-friendly sqc software for microcomputers

Major factors to consider in selecting a microcomputer SQC package are discussed, and a selection of low-cost user-friendly software is described. Functions of each package are considered in the context of their purchase cost and arrangements for reproduction. Focus is on the classroom, but this software is also suitable for use in industry and commerce.     

Approximation of the Fisher price index by using Lowe,Young, and AG Mean indices

The Consumer Price Index (CPI) approximates changes in the costs of household consumption assuming the constant utility (COLI, Cost of Living Index). In practice, the Laspeyres price index is used to measure the CPI despite the fact that many economists consider the superlative indices to be the best approximation of COLI. The Fisher index is one of the superlative indices and additionally it satisfies most of tests from the axiomatic price index theory. Nevertheless, the Fisher price index makes use of current-period expenditure data and its usefulness in CPI measurement is limited. In this article, we verify the utility of using the Lowe, Young, and AG Mean indices for Fisher price index approximation. We confirm this utility in a simulation study and we provide an empirical proof.     

Randomization and blocking in the design of experiments

It is suggested that, whenever possible, an experiment be run in a completely randomized fashion. One reason for randomizing Is to protect against violations in the usual linear model assump¬tions. The protection has always been argued on qualitative grounds. This paper quantitatively demonstrates the protection by hypothesizing models in violation of the usual assumptions, mathe¬matically representing the physical act of randomization, and algebraically deriving expected mean squares, EMS, and F tests. It is shown that randomization offers considerable but not com¬plete protection against model violations.

The same methodology is also applied to blocked experiments, i.e. to experiments performed under a specific type of incomplete randomization commonly referred to as blocking. It is shown that blocking offers little protection against certain model viola¬tions. The common practice of representing blocks as a treatment factor applied to the experimental units approximates the form of the EMS derived under the violated assumptions model.     

Estimation of the process incapability index

Greenwich and Jahr-Schaffrath (1995) introduced a new index C _pp a simple transformation of the index C _pm , which provides an uncontaminated separation between information concerning process accuracy and process precision. Under the assumption of normality, we first show that the estimators of C _pp proposed by Greenwich and Jahr-Schaffrath (1995) are UMVU estimators. We also show that for the inaccuracy index, the variance of the unbiased estimator is smaller than the mean squared error (MSE) of the natural (biased) estimator for n > 3. In addition, we obtain the r-th moment and the probability density function of these estimators.     

Index method of determining the sample size

To quantify how worthy and reliable an interval estimate of a parameter, an index is defined. This index is derived for estimating the mean μ of a normal population. Using this index, a method is devised for determining the sample size formula. Advantages of this new sample size formula are pointed out.     

区间灰数序列的白化方法及其性质研究

由于灰代数运算体系尚不完善,难以有效构建基于灰数序列的灰色模型,而传统灰数序列的白化方法又将导致信息损失,故在不破坏区间灰数独立性及信息完整性的前提下,设计一种区间灰数序列白化处理的新方法,重点研究白化序列与原区间灰数序列在平移变换及倍乘变换过程中的数据特点;同时将白化序列成功地应用于区间灰数预测及关联分析模型的构建。这一研究成果对拓展灰色模型的适用范围具有重要意义。     

关于物价综合指数性质的探析

通过对拉氏和帕氏物价指数的讨论，明确了物价综合指数之间的相互关系和物价综合指数的数学性质，找到了物价综合指数的变化特点。在保持原有指数特性的前提下，提出了新的综合指数改进方案，并对其进行了检验。检验表明，新的综合指数方案计算简便，能够准确地反映物量和价格的变化，并且误差较小。     

基于人口特征的收入差距分解分析——以重庆市为案例

 摘　　要:本文使用2005年全国1％人口抽样调查中重庆市的抽样调查数据，同时采用基于人口特征的收入群体分解和基于回归方程的收入来源分解二种方法考察了重庆市居民的各种人口特征对收入分配差距的影响。研究结果表明城乡差异是现阶段居民收入分配差距偏大的主要原因，特别是城乡居民之间受教育机会、职业选择上巨大的机会不平等将对收入分配差距扩大产生长期的影响。     

The performance of the truncated mixed control chart

Abstract

When the mixed chart proposed by Aslam et al. (2015 Aslam, M., M. Azam, N. Khan, and C.-H. Jun. 2015. A mixed control chart to monitor the process. International Journal of Production Research 53 (15):4684–93. doi:10.1080/00207543.2015.1031354.[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) is in use, the sample items are classified as defective or not defective and, depending on the number of defectives, the quality characteristic X of the sample items are also measured. In this case, an Xbar chart decides the state of the process. The previous conforming/non-conforming classification truncates the X distribution and, because of that, the mathematical development to obtain the ARLs is complex. Aslam et al. (2015 Aslam, M., M. Azam, N. Khan, and C.-H. Jun. 2015. A mixed control chart to monitor the process. International Journal of Production Research 53 (15):4684–93. doi:10.1080/00207543.2015.1031354.[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) didn’t pay attention to the fact that the X distribution is truncated and, due to that, they obtained incorrect ARLs.     

Precision Index in the Multivariate Context

General multivariate quantiles are employed to extend the classic univariate process precision index to the multivariate context under very mild conditions. Using halfspace depth regions for this purpose is especially recommended because it leads to both computational simplicity and natural generalizations to the tool-wear setup thanks to some recent advances in multiple-output and projectional quantile regression. A few examples are included to illustrate how the methodology might work in practice.     

Parameter Estimation Algorithms for the Hyper-Gamma Distribution Class

Microcomputer-based algorithms for the estimation of the parameters shift, scale, initial and terminal shape of the hyper–Gamma distribution class are presented. They are based on the moment equations and on the logarithmic likelihood function (LLF) associated with the hyper-Gamma density. The maximum–likelihood approach is implemented by means of the derivative equations resulting from the LLF and, independently, by means of direct optimization of the LLF. Program options include estimation of (i) four parameters, (ii) three parameters (shift known), and (iii) two parameters (shift known, initial shape zero). A program diskette with user's guide will be made available upon request.     

陕西省利用外商直接投资绩效分析

在前人研究FDI时忽略其时滞性和累积性特点的前提下，利用陕西省1985—2006年的时间序列数据，采用实际利用FDI存量对陕西省经济发展的作用作了计量检验。结果表明，在这段时间里FDI对陕西省GDP的增长和产业结构升级都有显著的促进作用，并且西部大开发后的作用明显大于开发前，FDI是陕西经济增长的一个重要因素。在此基础上对实际利用外商直接投资的业绩指数和潜力指数进行分析，发现陕西省利用外资规模水平长期严重低于全国平均水平，成为影响陕西省经济增速的一个原因；通过潜力指数分析发现，陕西省吸引外资的潜力居西部首位，并得出科研支出和高等教育人才是陕西省吸引外资的优势，出口少和人均能源消耗少是吸引外资的瓶颈。最后提出进一步吸引外资、促进陕西经济发展的政策建议。     

中国省域创新创业环境评价指标体系的构建研究——对全国31个省级单位的测评

围绕创新创业环境的内涵,梳理了影响创新创业环境的六类主要因素,归纳潜在指标;对各潜在指标进行"聚类—因子—权重"综合分析,提炼影响创新创业环境的主要因子,构建出以6个一级指标和20个二级指标为核心的创新创业环境评价指标体系,并建立评价模型。以中国各省为样本,对全国31个省级单位的创新创业环境在2014年的状况进行测评排序。依据各省创新创业环境综合得分情况,得出全国31省2014年创新创业环境的地理空间分布图。分地区评价结果显示,东部地区创新创业环境具有明显优势,中部、东北和西部地区发展空间较大。从准则层指出各个地区优化创新创业环境的着力点。     

基于业绩指数和潜力指数的西部地区民间投资绩效研究

通过修正联合国贸发会议(UNCTAD)《2002年世界投资报告》中的业绩和潜力指标,结合中国民间投资发展的现实,运用业绩和潜力指数对西部12省区民间投资的绩效进行了定量研究,结果显示:西部开发以来,12省份民间投资的业绩指数上升较为明显,但潜力指数提升幅度不大;省间民间投资绩效发展不平衡,且差距有升有降;民间投资业绩与潜力指数排序一致的比例较高,但同时存在相背离的现象.西部各省应当充分发挥比较优势和区位优势,明确投资目标,提高民间投资效率.     

Beyond the CPI: An Augmented Cost-of-Living Index

This note examines an augmented cost-of-living index (ACOLI) for the purpose of accounting for “augmented consumption” in real-income measures. Well-being includes not only conventional consumer purchases but also goods and services provided by employers, by mandated social regulations, and by tax-financed public goods. Because augmented consumption is often provided in ways that raise prices but not market incomes, deflating with conventional price indexes may understate real income growth. An exploratory application of the ACOLI approach to the United States during the 1960–1997 period suggests that the Consumer Price Index has grown about 19% faster than the ACOLI. This correction would reduce the estimated cost-of-living increase by .47% per year over the last 37 years.     

Evaluation of the bias of the isotonic regression

The systematic error (bias) of the isotonic regression analysis of temporal spacings between failure events is investigated by means of numerical simulation. Spacings that are sampled from an exponential distribution with a constant failure rate (CFR) arc subjected to an isotonic regression search for a declining failure rate (DFR). The results indicate a considerable declining trend (bias) that is imposed upon these CFR-data by isotonic regression analysis. The corresponding results for an increasing trend can be readily obtained through transformation. For practical applications, the results of 100,000 simulations have been approximated by simple analytical expressions. For the evaluation of a trend in a specific set of isotonized spacings (or rates) the results of the latter analysis can be compared with the isotonic bias of a set of CFR data for the same number of events. Alternatively, the specific set of isotonized spacings can be suitably related to the corresponding isotonized CFR data to reduce the bias by largely eliminating the CFR contribution.     

A remark on the estimation of the eose of directions of fibre processes

A method of estimation of the rose of directions of fibre processes is suggested which bases on the measurement of intersection angles with suitable test curves.     

Compliance of the Token-Bucket Model with Markovian Traffic

Abstract

Recently, risk processes have been analyzed as fluid queues. That approach is adapted here to the analysis of the token bucket model for Markovian traffic patterns. This paper presents the Laplace transform of the time until a given traffic pattern is not compliant anymore with a particular token bucket model.