Railway reforms: Do they influence operating efficiency?

This paper considers railway operations in 23 European countries during 1995-2001, where a series of reform initiatives were launched by the European Commission, and analyses whether these reform initiatives improved the operating efficiency of the railways. Efficiency is measured using Multi-directional Efficiency Analysis, which enables investigation of how railway reforms affect the inefficiencies of specific cost drivers. The main findings are that the reform initiatives generally improve operating efficiency but potentially differently for different cost drivers. Specifically, the paper provides clear empirical evidence that accounting separation is important for improving operating efficiency for both material and staff costs, whereas other reforms only influenced one of these factors.European railways; reforms; operating efficiency; Multi-directional Efficiency Analysis (MEA)

Glucose-Insulin Dynamical Model for Type 2 Diabetic Patients

In this paper, a literature review is made for the current models of glucose-insulin dynamics of type 2 diabetes patients. Afterwards, a model is proposed by combining and modifying some of the available models in literature to take into account the effect of multiple glucose meals, multiple metformin doses, insulin injections, physical exercise, and stress on the glucose-insulin dynamics of T2D patients. The model is proposed as a candidate to be validated with real patients data in the future

An Online Stochastic Optimization Approach for Insulin Intensification in Type 2 Diabetes with Attention to Pseudo-Hypoglycemia

In this paper, we present a model free approach to calculate long-acting insulin doses for Type 2 Diabetic (T2D) subjects in order to bring their blood glucose (BG) concentration to be within a safe range. The proposed strategy tunes the parameters of a proposed control law by using a zeroth-order online stochastic optimization approach for a defined cost function. The strategy uses gradient estimates obtained by a Recursive Least Square (RLS) scheme in an adaptive moment estimation based approach named AdaBelief. Additionally, we show how the proposed strategy with a feedback rating measurement can accommodate for a phenomena known as relative hypoglycemia or pseudo-hypoglycemia (PHG) in which subjects experience hypoglycemia symptoms depending on how quick their BG concentration is lowered. The performance of the insulin calculation strategy is demonstrated and compared with current insulin calculation strategies using simulations with three different models.Comment: Preprint for a paper accepted and presented at CD

Gamma-hydroxybutyrate and cocaine intoxication in a Danish child

GHB intoxication must be considered in children with coma and a suspicion of drug intoxication. Furthermore, mixed intoxication with several substances and the possibility of unpredictable symptom profiles should be anticipated to ensure optimal symptomatic treatment of patients

Measuring inefficiency in the Norwegian bus industry using multi-directional efficiency analysis

To measure and analyze efficiency in the transportation industry, this paper introduces and demonstrates the advantages of multi-directional efficiency analysis (MEA) in the case of cost data with limited substitution possibilities. Norwegian bus data that has previously been analyzed using econometric models and data envelopment analysis is reconsidered using MEA. Findings show that using MEA makes it possible to disaggregate inefficiency into different components corresponding to different types of cost generating variables and thereby provides both managers of the bus companies and policy makers with more detailed information on possible improvements in performance. Specific results show that about 10% higher costs for companies operating in coastal areas are related to inefficient utilization of the fuel input. This suggests that part of the improvement potential of companies in coastal areas is caused by topographic factors and are thus beyond management control. Controlling for the costal effects shows that ownership has an effect on fuel utilization. The improvement potential in driver costs were found to be about 4% larger for public than for private companies