Two-stage flowshop earliness and tardiness machine scheduling involving a common due window

This paper studies a non-preemptive two-stage flowshop scheduling problem to minimize the earliness and tardiness under the environment of a common due window. The window size and the window location are considered to be given parameters. The just-in-time problem exists naturally and has many practical applications. The problem is shown to be NP-complete in the strong sense. We develop a branch and bound algorithm and a heuristic to solve the problem. We conduct the computational experiments to test the performances of the algorithms. A strong lower bound is derived for the branch and bound algorithm that can efficiently solve 15 jobs problem for about 5 minutes. The heuristic is shown to be efficient and effective, which can solve the problem of 150 jobs for about 20 seconds and provide near-optimal solution. We justify that the heuristic is an excellent solution approach for large problem instances. We also show that four special cases are either polynomial solvable or NP-complete in the ordinary sense.     

Impact of fit,involvement, and tenure on job satisfaction and turnover intention

This study examined the interactive effects of need–supplies fit, job involvement, and job tenure on service sector employees' job satisfaction and turnover intention in Turkey. Survey data collected from 252 employees who worked in three different banks and one logistics company operating in Istanbul, Turkey, confirm the three-way interaction in predicting employees' turnover intention. In particular, the effect of needs–supplies fit on turnover intention was found to be more strongly positive for longer tenured, highly involved employees. Results also reveal that while the three-way interaction does not predict job satisfaction, the two-way interaction between needs–supplies fit and job involvement is significant. Specifically, needs–supplies fit had a stronger effect on the job satisfaction of highly job-involved employees than those with lower levels of involvement. Certain implications of these results, as well as avenues for future research, are discussed.     

Market development and market efficiency: evidence based on nonlinear panel unit root tests

This study tests the weak form market efficiency of 32 European stock markets. Utilizing monthly data from June 2006 to June 2017, six different, newly developed nonlinear panel root tests were applied in three different groups of European markets: Frontier, Emerging and Developed. The results show that there is a meaningful relationship between different levels of economic development and the weak form market efficiency. Considering the nonlinear structure of the stock market indices, use of linear models might lead to wrong conclusions regarding market efficiency. Using several nonlinear panel root tests, the results of this study shed more light on the true data generating process of the stock market indices and more appropriately model market efficiency.     

High-capacity vehicles: an investigation of their potential environmental,economic and practical impact if introduced to UK roads

In the UK, the length of a goods carrying vehicle is limited to a maximum of 16.5 m for a standard articulated vehicle and 18.75 m for a draw-bar combination. This research has investigated the environmental, economic and practical impacts of expanding the volumetric carry capacity by increasing maximum length of vehicles to 25.25 m, while maintaining the maximum gross weight at the current UK limit of 44 tonne. The scope is limited to the consideration of 25.25 m vehicle variants that are currently in use in the Netherlands. The investigation was based on a variety of techniques that included bench research and case study modelling. It concludes that, although the picture is complex and there are a number of operational issues to be addressed, the introduction of high-capacity vehicles (HCVs) to the UK would yield valuable environmental and financial benefits at vehicle and operator level, provided that vehicle utilisation levels do not deteriorate as compared with current fleet. At the national level, financial benefits would be partially offset by infrastructure costs and there is some risk of environmental benefits being partially eroded by modal shift – but on both measures a net benefit is highly likely to remain. In addition, provided that appropriate risk control measures are adopted, use of HCVs is highly unlikely to have an adverse impact on road safety.     

Intercultural competence and expatriates

This study examines the simultaneous effects of employees' fit with their organization, job and supervisor on their job satisfaction, organizational commitment and turnover intention in Turkish banks by paying special attention to the moderating role of perceived organizational support (POS) in these relationships. Survey data collected from 213 employees who work in five different banks operating in Istanbul, Turkey, show that employees' value fit with their organization increases their job satisfaction and organizational commitment significantly while having no direct effect on their turnover intention. The results also suggest a positive association between employees' fit with their job (needs–supplies fit) and their job satisfaction along with the negative, direct impact of job fit on turnover intention. The hypothesized relationships between employees' value fit with their supervisor and selected employee outcomes are not supported. With respect to the moderating role of POS, the overall findings indicate that a high level of organizational support suppresses the effects of employees' value fit with their organization on their job satisfaction and organizational commitment as well as reducing the relationship between their job fit and job satisfaction and turnover intention.     

Effects of Service Standards Communication and Servant Leadership on Strategic Competence and Customer Orientation

Service standards communication and servant leadership are both important mechanisms to improve an organization＇s service process. Therefore, they are likely to affect strategic competence and customer orientation skills of organizations. In this research, customer orientation and strategic competence are undertaken in relation with servant leadership and service standards communication, using a sample of 106 Turkish firms＇ executive assistants. The results prove that service standards communication and servant leadership have a strong positive relationship with both strategic competence and customer orientation.