The umvue and bayes estimate of reliability of mixed failure time distribution

We study the reliability estimates of the non-standard mixture of degenerate (degenerated at zero) and exponential distributions. The Uniformly Minimum Variance Unbiased Estimator (UMVUE) and Bayes estimator of the reliability for some selective prior when the mixing proportion is known and unknown are derived. The Bayes risk is computed for each Bayes estimator of the reliability. A simulated study is carried out to assess the performance of the estimators alongwith the true and Maximum Likelihood Estimate (MLE) of the reliability. An example from Vannman (1991) is also discussed at the end of the paper.     

A test for gamma DFR alternative

In this article, a test for exponentiality against gamma DFR alternative based on a quadratic form of the logarithmic observations is proposed. The percentage points and the power of the test are computed through Monte-Carlo simulation. The test is seen to perform well as compared to a chi-square test proposed by Bain and Engelhardt(1975).     

Quantifying the Economic Impact of Hydraulic Fracturing Proppant Selection in Light of Occupational Exposure Risk and Functional Requirements

Selection of an effective and economic proppant material for hydraulic fracturing is an important design choice to optimize the production of oil and natural gas. Proppants are made of silica (quartz sand), alumina, resin-coated silica, ceramics, and others. These materials can be toxic to varying degrees and lead to health problems in the employees handling them primarily due to inhalation exposure. Proppants are selected based on grain size, shape, strength, and cost. Current use is dominated by crystalline silica—the proppant that also has the greatest hazard as an inhalation toxin. Existing research describes the effect of silica on human health, but little research has been done to determine the risk-reduction and social-cost-effectiveness associated with using alternative proppants in light of the health risks. This study quantifies the relative risks or benefits to human health by the use of these proppants through an economic analysis considering the health-related economic impact and its technical attributes. Results show that the use of each ton of silica proppant results in $123 of external costs from fatalities and nonfatal illness arising due to exposure to silica for a crew handing 60,000 tons of proppants. If these health-related externalities were incorporated into the cost, silica proppant could be economically replaced by less harmful, more expensive alternatives for hydraulic fracturing crews handling less than 60,000 tons of proppant each year.     

Application of control charts in analytic hierarchy process

Vendor rating can be done using the Analytic Hierarchy Process (AHP) by a single decision maker or a group of decision makers. This approach may suffer from some drawbacks including bias in estimation process. The proposed methodology in this paper involves estimation by a group on an individual basis following the principle of anonymity. A control chart is constructed with an upper control limit and a lower control limit. Implementation ofthiscontrol chart will take into account the dynamic nature of vendor performance and also can be used for continuous monitoring of the vendor performance. This procedure can be used for a single vendor as well as for multiple vendor rating.     

Some tests for a poisson process and their powers with respect to trend in the intensity

Recently many authors have worked on Wei bull process in the area of modelling and analysis. Much less work is done in the area of testing of hypothesis. In this article, some tests for testing the Poisson process against a class of Wei bull process based on the conditional distribution of observations given the sufficient statistic, are proposed. The percentage points of the distributions of the proposed test statistics are simulated. The powers of the tests under alternatives are computed by Monte Carlo method. It is seen that the suggested tests perform well for decreasing intensities.     

Integration of IPA and QFD to assess the service quality and to identify after sales service strategies to improve customer satisfaction – a case study

Customer satisfaction is considered very essential nowadays as it shows how firms are dedicated to afford quality products or services to their customers. Retaining the existing customer and acquiring the new customers are the basic objectives of any organisation and after sales service (ASS) has acquired a strategic role as a mean to achieve customer satisfaction. Importance–performance analysis (IPA) and quality function deployment (QFD) are the powerful tools successfully applied in many fields. However, studies on application of these tools in investigating the ASS quality and customer satisfaction seems to be scarce. This article investigates linking of IPA, which is a simple and effective customer satisfaction tool and QFD in the improvement of ASS attributes in an effort to determine the appropriate ASS strategic action plans to be adopted with the objective of enhancing customer satisfaction. In this study, a customer-driven model is proposed to examine the importance of the various ASS attributes and the performance of the organisation via questionnaire survey, and through the IP analysis, the areas to be focused are identified to help the decision makers in devising suitable policies, to improve the ASS performance. This is achieved through the employment of QFD that will help decision makers in the strategic planning to attain better customer satisfaction. A case study is carried out to exhibit the effectiveness of the developed model in a firm involved in manufacturing the home appliances.     

Spoofing: social commentary or effective marketing tool? Testing promotion vs. prevention message frames in college students’ fight against obesity

Spoofs parody regular advertisements in an attempt to discourage consumers from using or buying certain products. Using regulatory focus theory, the overarching question in this paper was whether spoofs (promotion vs. prevention) act as anti-consumption messages to fight obesity among college students. In Study 1, a repeated measures design was employed where participants were shown the regular ad followed by either spoof, while in Study 2, a between-subjects design was used and participants were exposed to either one of the three ads. Findings from both studies confirmed that spoofing potentially impacts brands, specifically, purchase intentions. Effectiveness of either spoof varies with respect to the presentation order of the ads and levels of anti-commercial consumer rebellion. Theoretical and managerial implications are discussed.     

The Gulf Coast oil spill: Extending the theory of image restoration discourse to the realm of social media and beyond petroleum

The explosion of Transocean's Deepwater Horizon, an oil-rig licensed to BP, set in motion a chain of unfortunate events that led to BP's ruptured oil well disgorging millions of gallons of oil into the Gulf of Mexico. Since the spill, the corporate image of BP has been severely challenged. The company has used many strategies to preserve and restore the corporate image, and has sought means to mitigate the intensity of the ongoing threat to individuals, businesses, and a delicate ecosystem. Among these means are interacting with individuals and interest groups through social media channels. Benoit's (1995) theory of image restoration discourse posits various strategies corporations use to restore their image during a crisis. The BP crisis presents an opportunity to extend the theories of image restoration to the realm of social media. Results of a content analysis showed that corrective action was the dominant image restoration strategy employed by BP in their Facebook, Twitter, YouTube and Flickr pages. A high presence of negative emotions revealed that corrective action was not an effective means of swaying public opinion in favor of BP's efforts. Dominant themes in all four social media channels and audience comments in terms of dominant issues and emotions on Facebook and YouTube were also analyzed.     

Hope for Haiti: An analysis of Facebook and Twitter usage during the earthquake relief efforts

The Haitian earthquake devastated the small island of Hispaniola, leaving thousands dead and billions of dollars in property damage. The earthquake also ignited a firestorm of social media use by organizations. By applying framing theory to the analysis of Facebook posts and tweets sent by nonprofits and media organizations, this study discovered differences between nonprofits and media in terms of social media use. Nonprofits and media organizations used information dissemination and disclosure effectively, but failed to capitalize on the innate two-way communication nature of social media.