Catch-up as a Survival Strategy in the Solar Power Industry

We evaluate the strategies of the emerging market firms in the context of nascent industries. We use the Indian solar power industry as the empirical setting, against the backdrop of the evolution of the global industry, While in traditional industries emerging market firms learn from advanced economy multinational enterprises (MNEs) and slowly upgrade their capabilities, in the intensely competitive environment of nascent innovative industries, emerging market firms are exposed to global competition in their home market right from the early years. This shortens their catch-up clock. As a result, their long-term survival depends on their ability to catch-up fast, both in output and innovation capabilities. In the solar power industry, we find that innovations stem, in the main, from advanced economy firms. Further, Chinese firms are beginning to move from cost-based imitation to innovation. In contrast, with a few key exceptions, most firms in the Indian solar industry remain locked within a narrow niche of downstream site-based installation. Their operations are opportunistic, short term, and without specific catch-up goals, a scenario that does not bode well for the industry's future in India.     

Confidence intervals for the ratio of two variances

In this paper we consider confidence intervals for the ratio of two population variances. We propose a confidence interval for the ratio of two variances based on the t-statistic by deriving its Edgeworth expansion and considering Hall's and Johnson's transformations. Then, we consider the coverage accuracy of suggested intervals and intervals based on the F-statistic for some distributions.     

Robust dual-CUSUM control charts for contaminated processes

ABSTRACT

In this article, we improve the efficiency of the Dual CUSUM chart (which combines the designs of two CUSUM structures to detect a range of shift) by focusing on its robustness, ability to resist some disturbances in the process environment and violation of basic assumptions. We do that, by proposing some robust estimators for constructing the chart for both contaminated and uncontaminated environments. The average run length is used as the performance evaluation measure of the charts. After comparing the performances of the proposed charts based on the estimators, it is noticed that the tri-mean estimator out-performs others in all ramifications. Next to it in performance is the Hodges-Lehmann and midrange estimators. We substantiated the simulation results of the study by applying the scheme on a real-life data set.