Stochastic analysis of covariance when the error distribution is long-tailed symmetric

In this study, we consider stochastic one-way analysis of covariance model when the distribution of the error terms is long-tailed symmetric. Estimators of the unknown model parameters are obtained by using the maximum likelihood (ML) methodology. Iteratively reweighting algorithm is used to compute the ML estimates of the parameters. We also propose new test statistic based on ML estimators for testing the linear contrasts of the treatment effects. In the simulation study, we compare the efficiencies of the traditional least-squares (LS) estimators of the model parameters with the corresponding ML estimators. We also compare the power of the test statistics based on LS and ML estimators, respectively. A real-life example is given at the end of the study.     

Optimal Pricing Strategies for Capacity Leasing Based on Time and Volume Usage in Telecommunication Networks

In this study, we examined optimal pricing strategies for “pay‐per‐time,” “pay‐per‐volume,” and “pay‐per‐both‐time‐and‐volume” based leasing of data networks in a monopoly environment. Conventionally, network capacity distribution includes short‐/long‐term bandwidth and/or usage time leasing. When customers choose connection‐time–based pricing, their rational behavior is to fully utilize the bandwidth capacity within a fixed time period, which may cause the network to burst (or overload). Conversely, when customers choose volume‐based strategies their rational behavior is to send only the minimum bytes necessary (even for time‐fixed tasks for real time applications), causing the quality of the task to decrease, which in turn creates an opportunity cost for the provider. Choosing a pay‐per time and volume hybridized pricing scheme allows customers to take advantage of both pricing strategies while lessening the disadvantages of each, because consumers generally have both time‐ and size‐fixed tasks such as batch data transactions. One of the key contributions of this study is to show that pay‐per both time and volume pricing is a viable and often preferable alternative to the offerings based on only time or volume, and that judicious use of such a pricing policy is profitable to the network provider.     

The Role of Progress Factors Explaining Inefficiencies in Transition Countries

This paper examines whether progress in transition has a significant effect on the economic efficiency for 24 transition countries from 1990 to 2006. It uses nine progress factors to analyze the role of the progress factors to explain inefficiencies. It also questions the effect of the transition countries that recently joined the European Union on efficiency. The results suggest that the average efficiency scores for EU-N10 are much higher than the average efficiency scores for SEE/CIS. The scores increase over time for both groups of transition countries. Reforms also contribute to efficiency in general.     

A new painting process for vessel radiators of transformer: wet-on-wet

The painting process of corrugated wall radiators of a distribution transformer is performed by a flow-down painting technique in the industrial field. This study has been prepared in accordance with ISO 12944-5. Correspondingly, this work is motivated by Epoxy 2-pack paints (4.3.4.2) to obtain minimum requirements for C3 atmospheric corrosivity categories (5.1.1). This standard requires from the vertical surface of the vessel of the transformer to be painted with epoxy paints that contain anti-corrosive pigments with a minimum of 100?µm dry film thickness. In the present study, a new production methodology called wet-on-wet (WOW) painting is developed which has never been used in industry. In addition, a modified response surface methodology (RSM) is proposed for designing, modeling, and optimizing the proposed process under unsteady environmental effects. The results indicate that the WOW painting can be applied to real industrial systems successfully by the aid of the proposed new RSM algorithm and provide remarkable time and cost savings.     

CEO Duality,Agency Costs,and Internal Capital Allocation Efficiency

This study examines the impact of CEO duality on firms’ internal capital allocation efficiency. We observe that when the CEO is also chair of the board, diversified firms make inefficient investments, as they allocate more capital to business segments with relatively low growth opportunities over segments with high growth opportunities. The adverse impact of CEO duality on investment efficiency prevails only among firms that face high agency problems, as captured by high free cash flows, staggered board structure and low board independence. Depending on the severity of the agency problem, CEO duality is associated with a decrease in industry‐adjusted investment in high‐growth segments of 1% to 2.1% over the following year, relative to that in low‐growth segments. However, CEOs’ equity‐based compensation curbs the negative effect of CEO duality on internal capital allocation efficiency. Overall, the findings of this study offer strong support for the agency theory and postulate the internal capital allocation policy as an important channel through which CEO duality lowers firm value in diversified firms.     

One-step M-estimators: Jones and Faddy's skewed t-distribution

One-step M (OSM)-estimator needs some initial/preliminary estimates at the beginning of the calculation process. In this study, we propose to use new initial estimates for the calculation of the OSM-estimator. We consider simple location and simple linear regression models when the distribution of the error terms is Jones and Faddy's skewed t. Monte-Carlo simulation study shows that the OSM estimator(s) based on the proposed initial estimates is/are more efficient than the OSM estimator(s) based on the traditional initial estimates especially for the skewed cases. We also analyze some real data sets taken from the literature at the end of the paper.