Designing a multiple state repetitive group sampling plan based on the coefficient of variation

A multiple state repetitive group sampling (MSRGS) plan is developed on the basis of the coefficient of variation (CV) of the quality characteristic which follows a normal distribution with unknown mean and variance. The optimal plan parameters of the proposed plan are solved by a nonlinear optimization model, which satisfies the given producer's risk and consumer's risk at the same time and minimizes the average sample number required for inspection. The advantages of the proposed MSRGS plan over the existing sampling plans are discussed. Finally an example is given to illustrate the proposed plan.     

People as partners: Facilitating people's participation in public–private partnerships for solid waste management

Cities in developing countries are facing a double dilemma. On one hand, the urban population is growing rapidly, causing a huge increase in demand for waste management services. On the other hand, the traditional public sector is failing to respond to the increased demand for service. The public sector is constrained by resource and institutional limitations. It is often proposed that the solution lies in private sector participation. It is expected that the private sector, with its dynamism and flexibility, may fill in the service delivery gaps by forming partnership with the public sector. However, a third tier—the people—is often overlooked in the service delivery framework. Citizens can contribute significantly to service delivery. They can support the private sector with payment of service charges. But more importantly, they can play an active role in improving accountability and service quality of both public and private sector. This radical shift in people's role, from passive service receivers to active service partners, however, may not occur endogenously. External help from facilitating agencies may enable the public and private sector to form partnership with people for better service delivery. This article examines the role of facilitating agencies in developing tripartite partnership for solid waste management service in Bangladesh. The key lessons learned are: a number of obstacles prevented spontaneous partnership among the public sector, private sector and people; facilitating agencies were able to overcome the obstacles to form partnership of the three; and, the tripartite arrangement resulted in higher accountability and better service delivery.     

Developing a variables repetitive group sampling plan based on process capability index C pk with unknown mean and variance

In this paper, variables repetitive group sampling plans are developed based on the process capability index C _pk when the quality characteristic follows a normal distribution with unknown mean and variance. The sampling plan parameters such as the sample size and the acceptance constant are determined to minimize the average sample number. Symmetric and asymmetric cases, in percent defectives due to two specification limits, are dealt with for specified combinations of acceptable quality level and limiting quality level. Tables are provided and examples are given to use proposed plans in practice.     

Iranian obstetricians’ views about the factors that influence pregnant women's choice of delivery method: A qualitative study

BackgroundCaesarean section is a commonly performed childbirth procedure. While caesarean section is undeniably a lifesaving procedure for some mothers and babies, it can also be an unnecessary procedure for others. Different factors may be involved in the rate of birth by caesarean section.QuestionThis qualitative study was conducted in Kashan city, Iran, to explore obstetrician's views of what might influence pregnant women's choice of delivery method.MethodsObstetricians’ views and experiences were collected using semi-structured interviews. Interviews were conducted in a clinic or hospital, based on the preference of the 18 physicians who agreed to participate in the study. All interviews were recorded and transcribed. Participants were asked key questions, including: “Why do some women prefer caesarean section?”; “What kind of delivery did you have and why?”; “What kind of delivery would you recommend to pregnant women and why?” Inductive qualitative content analysis was undertaken using the method described by Morreti with 120 initial codes categorized into six categories.FindingsThe six categories developed from the initial codes were: factors relating to women, obstetricians, delivery conditions, complications, society's beliefs and the health system.ConclusionA qualitative study conducted in Iran showed that most of the factors identified by participants facilitated the choice of caesarean section. Vaginal birth was anticipated as a painful and lengthy process, with low cultural acceptance and resulting in less income for obstetricians.     

Mixed sampling plan based on exponentially weighted moving average statistic

ABSTRACT

We will design a new mixed acceptance sampling plan based on the exponentially weighted moving average statistic in this article. The plan parameters of the proposed plan are determined by an optimization problem. The efficiency of the proposed plan is compared with the existing attribute sampling plan. An industrial example is given for illustration purpose.     

A note on the conditional residual lifetime of a coherent system under double monitoring

In this note, we derive some mixture representations for the reliability function of the conditional residual lifetime of a coherent system with n independent and identically distributed (i.i.d.) components under the condition that at time t₁ the jth failures has occurred and at time t₂ the kth failures (j < k) have not occurred yet. Based on the mixture representations, we then discuss the stochastic comparisons of the conditional residual lifetimes of two coherent systems with i.i.d. components.     

A HEWMA-CUSUM control chart for the Weibull distribution

The Weibull distribution is one of the most popular distributions for lifetime modeling. However, there has not been much research on control charts for a Weibull distribution. Shewhart control is known to be inefficient to detect a small shift in the process, while exponentially weighted moving average (EWMA) and cumulative sum control chart (CUSUM) charts have the ability to detect small changes in the process. To enhance the performance of a control chart for a Weibull distribution, we introduce a new control chart based on hybrid EWMA and CUSUM statistic, called the HEWMA-CUSUM chart. The performance of the proposed chart is compared with the existing chart in terms of the average run length (ARL). The proposed chart is found to be more sensitive than the existing chart in ARL. A simulation study is provided for illustration purposes. A real data is also applied to the proposed chart for practical use.     

A control chart for monitoring process variation using multiple dependent state sampling

A control chart for monitoring process variation by using multiple dependent state (MDS) sampling is constructed in the present article. The operational formulas for in-control and out-of-control average run lengths (ARLs) are derived. Control constants are established by considering the target in-control ARL at a normal process. The extensive ARL tables are reported for various parameters and shifted values of process parameters. The performance of the proposed control chart has been evaluated with several existing charts in regard of ARLs, which empowered the presented chart and proved far better for timely detection of assignable causes. The application of the proposed concept is illustrated with a real-life industrial example and a simulation-based study to elaborate strength of the proposed chart over the existing concepts.     

Emigration dynamics in Pakistan

This study of emigration dynamics in Pakistan focuses on Pakistan's position as one of the world's leading manpower exporters. The study opens with a review of the history of international labor from the subcontinent. The second section looks at the problems with the collection of data on international migration and then considers the volume of international migration, migrant destinations, return migration, undocumented migration, and the stock of migrant workers abroad. The third section describes the economic and demographic context for overseas migration through a consideration of gross national product and the remittances of migrant workers, growth in gross domestic product, poverty and income distribution, the state of the population, labor force and employment, a profile of migrant workers, and the government's employment policy. The political and social context for overseas migration is the topic of the next section, and the discussion centers on emigration policy, institutional arrangements for manpower export and the welfare of migrants, and the economic resettlement of return migrants. Consideration of the future trends in international migration from Pakistan focuses on the cyclic nature of overseas labor migration, the existence of networks to facilitate such migration, uneven distribution of enabling resources in Pakistan, the paucity of available data, and governmental/cultural factors that promote and restrict such migration. It is concluded that both individual Pakistanis and the government consider overseas migration a positive force but that a reliance on such an ad hoc measure has costs that have not been considered by Pakistan's policy-makers.     

A Distributional Analysis of Public–Private Wage Differential in India

In this paper, we examine public–private wage differential among men in India across the entire wage distribution. We find that the raw wage gap between public and private sector is positive across the entire wage distribution in both urban and rural areas. A quantile regression‐based decomposition reveals that that the public sector workers enjoy a positive wage premium across the entire wage distribution in both urban and rural areas, although the magnitude of wage premium is smaller at the top quantiles.