By considering various stochastic disturbances unfolding in a real-time dispatching environment, this paper develops a stochastic optimization formulation for incorporating segment travel-time uncertainty and dispatching policies into a medium-term train-timetabling process that aims to minimize the total trip time in a published timetable and reduce the expected schedule delay. Based on a heuristic sequential solution framework, this study decomposes the robust timetabling problem into a series of subproblems that optimize the slack-time allocation for individual trains. A number of illustrative examples are provided to demonstrate the proposed model and solution algorithms using data collected from a Beijing-Shanghai high-speed rail corridor in China.

The purpose of this study is to investigate the ways of achieving Science, Technology and Innovation (STI) in UAE. Previously, sustainability within an entrepreneurship context has been related to economic viability as opposed to sustainability in its broadest sense. Through a survey research method, we have highlighted the effects of three independent variables and two intervening variables on three important outcomes, innovation, need for achievement and motivation, which ultimately contributes towards STI. These data have been collected from the students of a well-known university in Al-Ain, UAE. The responses of 251 students have been utilized for analysis. For hypotheses testing, we used AMOS 18 (Structural Equation Modeling) and SPSS 20. The study revealed that all of the predictors have a strong effect on the outcome variables, which leads to STI in UAE. There is a strong need to revise the curriculum of higher education institutions of UAE to develop self-confidence, locus of control and risk taking propensity among students. The study provides novel insight into entrepreneurship education and serves as an initial benchmark in the field.

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Background:The management of cerebrospinal fluid (CSF) rhinorrhea has evolved over the last two decades. We present here a review of our 11-year data on CSF rhinorrhea and its management at a tertiary care hospital in a developing country, with particular reference to the diagnosis, surgical management and outcome of the disease.Methods:The medical charts of all patients with a diagnosis of CSF rhinorrhea over an 11-year period were reviewed. The etiology of CSF rhinorrhea was classified into three categories: spontaneous, iatrogenic and traumatic. All the patients were divided into three categories based on the type of management as conservative, intracranial and transnasal endoscopic groups.Results:A total of 43 patients fulfilled our inclusion criteria and were included in the final analysis. Eleven of the 43 patients were managed conservatively, while 22 underwent intracranial repairs; 10 patients had transnasal endoscopic repairs. The primary success rate for the transnasal approach was 70% compared to 86% for the intracranial repair. Blood loss, special care unit (SCU) stay and total cost were found to be significantly less in the transnasal endoscopic group. Computed tomography (CT) cisternography was found to have the highest sensitivity and specificity. Further, no postoperative complications were found in the transnasal endoscopic group, while five patients from the intracranial group developed various complications.Conclusions:We conclude that the transnasal endoscopic approach has comparable success rates with the intracranial approach and significantly lower morbidity.

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