A Comparison of the Performance of Phase II Simple Linear Profile Control Charts when Parameters are Estimated

The standard deviation of the average run length (SDARL) is an important performance metric in studying the performance of control charts with estimated in-control parameters. Only a few studies in the literature, however, have considered this measure when evaluating control chart performance. The current study aims at comparing the in-control performance of three phase II simple linear profile monitoring approaches; namely, those of Kang and Albin (2000), Kim et al. (2003), and Mahmoud et al. (2010). The comparison is performed under the assumption of estimated parameters using the SDARL metric. In general, the simulation results of the current study show that the method of Kim et al. (2003) has better overall statistical performance than the competing methods in terms of SDARL values. Some of the recommended approaches based solely on the usual average run length properties can have poor SDARL performance.     

对孙楚赋作的分析

孙楚,西晋前期文士,文名颇高,但其赋作鲜少被今人提及。根据严可均辑《全上古三代秦汉三国六朝文》《全晋文》卷六十,孙楚留存的赋作有十七篇,且皆是咏物短制,这篇文章将从题材扩大、篇幅皆短、好用典故、兴寄不多这四个方面分析孙楚赋作的特色,从中亦可以看出那个时代咏物赋的一些共同特点。     

Hungarian verbal puzzles and the intensity of language contact

Grammaticality judgments of bilingual Hungarians in Slovakia and Ukraine vs. Yugoslavia show that overt objects are much more acceptable in the northern Slavic countries than in Yugoslavia. Two conflicting hypotheses have been advanced to explain this difference. The structural hypothesis claims that Serbian cliticization is responsible, while the socio-historical hypothesis claims that the difference in grammaticality judgments is due to a difference in the duration of Hungarian–Slavic language contact north of and south of present-day Hungary. Data from a seven-country survey (N = 846) show that there is a split between judgments in the northern vs. southern Slavic countries across a wide range of linguistic variables, which discredits the structural explanation for the object pro-drop variable, at least as the sole cause of change. Moreover, statistical analyses of 24 variables provide substantial empirical verification of Thomason and Kaufman's 'two crucial parameters of intensity of contact in a borrowing situation': time and level of bilingualism. It is shown that the 250 years of contact between Hungarian and Serbian has resulted in much smaller contact effects than the thousand-year-old contact of Hungarian with the northern Slavic languages. Bilingual Hungarians who constitute a local minority in the settlements where they live systematically favor the contact-induced variants of variables vis-a`-vis those who constitute a local majority.     

Explicit Formulae for the Queue Length Distribution of Batch Arrival Systems

Abstract

A G ^θ I/G/1-type batch arrival system is considered. Explicit formulae for the distribution of queue length both at the fixed time t and as t → ∞ are obtained. The study is based on the generalization of Korolyuk's method for semi-markov random walks.     

The Effect of Methods for Handling Missing Values on the Performance of the MEWMA Control Chart

This article is concerned with the effect of the methods for handling missing values in multivariate control charts. We discuss the complete case, mean substitution, regression, stochastic regression, and the expectation–maximization algorithm methods for handling missing values. Estimates of mean vector and variance–covariance matrix from the treated data set are used to build the multivariate exponentially weighted moving average (MEWMA) control chart. Based on a Monte Carlo simulation study, the performance of each of the five methods is investigated in terms of its ability to obtain the nominal in-control and out-of-control average run length (ARL). We consider three sample sizes, five levels of the percentage of missing values, and three types of variable numbers. Our simulation results show that imputation methods produce better performance than case deletion methods. The regression-based imputation methods have the best overall performance among all the competing methods.     

无限长理想导体圆柱对电磁导弹的散射

最近的研究表明,当一个能量按r~(-(?))衰减的电磁导弹投射到无限长平板后,其散射场能量仍按r~(-(?))衰减。电磁导弹在其它目标上的散射特性是一个尚待研究的课题。本文讨论能量按r~_(-(?))衰减的电磁导弹在理想金属圆柱上的散射特性。研究表明,电磁导弹散射场的能量衰减规律正比于r_(-(1+(?)))。这说明在入射场为电磁导弹的情形下,金属圆柱体的散射场能量衰减比平板要快,但仍比常规二维散射场的能量衰减规律r~(-2)要慢。     

一种有向图并行性拓扑排序算法

论述了有向图并行性拓扑排序的基本概念及其算法,解决了目前有向图拓扑序列串行性的缺点,说明有向图并行拓扑排序具有应用范围广、实用价值大的特点.     

汉语语音特性对包交换通信中包化长度的影响

利用汉语语音的统计指数，从语音丢失的角度出发，分析了在语音数字综合业务网中，语音信号包化长度的变化对通信系统性能的影响，给出了包化长度所满足的数学表达式和实际计算值．     

Quality Control Chart for the Mean using Double Ranked Set Sampling

In this paper, an attempt is made to develop Quality Control Charts for monitoring the process mean based on Double Ranked Set Sampling (DRSS) rather than the traditional Simple Random Sampling (SRS). Considering a normal population and several shift values, the performance of the Average Run Length (ARL) of these new charts was compared with the control charts based on Ranked Set Sampling (RSS) and SRS with the same number of observations. It is shown that the new charts do a better job of detecting changes in process mean compared with SRS and RSS.     

横向扩展，纵向连锁，动静结合，创建思维新机制——广州人思维机制建构探索

本篇是系列论文第二篇，紧扣广州人思维机制建构问题展开。从广州人创建思维新机制看，思维是以横向扩展（“静”中有“动”）作基础，并以纵向推移（“静”“动”结合）作深化，最终实现纵横交错的动态系统，从而全面具体把握现实发展