On the improvement of one-sided S control charts

The most common charting procedure used for monitoring the variance of the distribution of a quality characteristic is the S control chart. As a Shewhart-type control chart, it is relatively insensitive in the quick detection of small and moderate shifts in process variance. The performance of the S chart can be improved by supplementing it with runs rules or by varying the sample size and the sampling interval. In this work, we introduce and study one-sided adaptive S control charts, supplemented or not with one powerful runs rule, for detecting increases or decreases in process variation. The properties of the proposed control schemes are obtained by using a Markov chain approach. Furthermore, a practical guidance for the choice of the most suitable control scheme is also provided.     

RESEARCH NOTE Some evidence against the assumption that approval of family planning is associated with frequency of spouses' discussion of the subject

Much previous work on the relationship between respondent's reported frequency of discussion with spouse about family planning and correctness of reporting spouse's approval of family planning has led to the conclusion that discussion promotes approval. In this paper, data from the 1998 Kenya Demographic and Health Surveys are used to show that a focus on the relationship between frequency of discussion and correctness of reporting partner's disapproval of family planning leads to sceptical conclusions about the effects of discussion in improving knowledge of partner's attitude or in promoting approval.     

Demography and Social Science

Research has demonstrated that son preference has a serious impact on the survival and well-being of female infants and children in some parts of South and East Asia, but little is known about the consequences of son preference in later childhood and adolescence. We compare children's growth trajectories in height over childhood and adolescence in China, where the level of son preference is relatively high, and the Philippines, where it is relatively low. Children's height reflects long-term nutritional status and exposure to infectious diseases, both influenced by household decision-making and, presumably, by a preference for sons. Using data from two high-quality longitudinal studies and multilevel growth models, we find that male children in China show an additional height advantage relative to their female counterparts, when compared to the sex difference in growth trajectories in the Philippines. Further analysis reveals that the additional advantage of males in China is stronger in rural areas.     

Accurate detection of excess over a standard based on a random sample

A known number N of packages each contain, in differing unknown amounts, both substances of no particular import and some substance of interest, the total weight of the latter substance for all N of the packages being an unknown quantity T. Based on the amounts of the substance of interest found in each of n (n ≦= N) randomly sampled packages one is to decide, with a very small probability of the error of wrongly deciding that T exceeds L, whether or not the quantity T exceeds a given amount L. An optimal way of doing this is presented in which the probability of the error of wrongly deciding that T exceeds L can be precisely bounded above as desired.     

Modular design of integrated databases in production management systems

Abstract

Complexity is a serious problem with respect to the application of information technology in the field of production management. This paper presents an overview of the more fundamental problems encountered and proposes a solution for some of those problems in the form of modular decomposition of the conceptual database structure. It is argued that the complexity of information systems is closely connected to the complexity of the organization. Therefore a condition for the realization of integrated information systems for production management is a simplification of the organizational structure by way of defunctionalization and the forming of autonomous units.     

A new prototype system for optimized job shop scheduling

Optimal scheduling of shopfloor activities in an environment of discrete part manufacturing is discussed. The scheduling problem is a well known NP complete one. The main part, the sequencing problem, has been tackled using two techniques: virtual resources identification and taboo search heuristics. The first approach allowed the authors to reduce the complexity of the sequencing from a job shop to a general flow shop problem. On the other hand, the search for an optimal solution, with respect to a fixed strategy, has been achieved via the taboo search. A synthesis of the results of a large number of tests is presented as well as the results of an application to a real case. The latter is shown in comparison with the output of the system being presently used in the examined factory.     

Study of a Markov model for a high-quality dependent process

For high-quality processes, non-conforming items are seldom observed and the traditional p (or np) charts are not suitable for monitoring the state of the process. A type of chart based on the count of cumulative conforming items has recently been introduced and it is especially useful for automatically collected one-at-a-time data. However, in such a case, it is common that the process characteristics become dependent as items produced one after another are inspected. In this paper, we study the problem of process monitoring when the process is of high quality and measurement values possess a certain serial dependence. The problem of assuming independence is examined and a Markov model for this type of process is studied, upon which suitable control procedures can be developed.     

Another look at fertility and social mobility

This is a response to Basil Zimmer's contention that the classical hypothesis connecting social mobility with fertility was rejected in the Princeton Fertility Study because of a faulty mode of analysis. Arguing from the findings of a strong association in a sample of Aberdeen women, Zimmer asserts that if social origin and destination were taken into account, the same relationship would have emerged in the U.S. data. The evidence from the Princeton Study is reviewed and new evidence presented which confirms the original findings of no relationship.     

FOREIGN DIRECT INVESTMENT AND ECONOMIC GROWTH: THE GROWTH ACCOUNTING PERSPECTIVE

A positive relationship between FDI and economic growth under two economic conditions has been estimated: a sufficient level of human capital and well-developed financial markets, respectively. However, these two conditions can be fundamentally different catalysts for FDI to promote economic growth in the perspective of growth accounting. Using data from 69 countries over 1970–1989, we find that FDI promotes productivity growth only when the host country reaches a threshold level of human capital; and FDI promotes capital growth only when a certain level of financial development is achieved. ( JEL F21)