Personnel Scheduling on Railway Yards

In this paper we consider the integration of the personnel scheduling into planning railway yards. This involves an extension of the Train Unit Shunting Problem, in which a conflict-free schedule of all activities at the yard has to be constructed. As the yards often consist of several kilometers of railway track, the main challenge in finding efficient staff schedules arises from the potentially large walking distances between activities. We present two efficient heuristics for staff assignment. These methods are integrated into a local search framework to find feasible solutions to the Train Unit Shunting Problem with staff requirements. To the best of our knowledge, this is the first algorithm to solve the complete version of this problem. Additionally, we propose a dynamic programming method to assign staff members as passengers to train movements to reduce their walking time. Furthermore, we describe several ILP-based approaches to find a feasible solution of the staff assignment problem with maximum robustness, which solution we use to evaluate the quality of the solutions produced by the heuristics. On a set of 300 instances of the train unit shunting problem with staff scheduling on a real-world railway yard, the best-performing heuristic integrated into the local search approach solves 97% of the instances within three minutes on average

How to Measure the Robustness of Shunting Plans

The general problem of scheduling activities subject to temporal and resource constraints as well as a deadline emerges naturally in numerous application domains such as project management, production planning, and public transport. The schedules often have to be implemented in an uncertain environment, where disturbances cause deviations in the duration, release date or deadline of activities. Since these disruptions are not known in the planning phase, we must have schedules that are robust, i.e., capable of absorbing the disturbances without large deteriorations of the solution quality. Due to the complexity of computing the robustness of a schedule directly, many surrogate robustness measures have been proposed in literature. In this paper, we propose new robustness measures, and compare these and several existing measures with the results of a simulation study to determine which measures can be applied in practice to obtain good approximations of the true robustness of a schedule with deadlines. The experiments are performed on schedules generated for real-world scheduling problems at the shunting yards of the Dutch Railways (NS)

Mild desalination demo pilot: New normalization approach to effectively evaluate electrodialysis reversal technology

AbstractKey performance indicators for characterization of nanofiltration performance are well developed, similar key performance indicators for electrodialysis reversal are however underdeveloped. Under the E4Water project Dow Benelux BV and Evides Industriewater BV operate a pilot facility to compare both technologies for their application to mildly desalinate a variety of brackish water streams. Normalized pressure drop, normalized current efficiency and normalized membrane resistance proved to be a useful tool to interpret process performance and to initiate a cleaning procedure if required. The availability of these normalized key performance indicators enables optimization and process monitoring and control of electrodialysis reversal independent of the continuously changing conditions of the feed water

Artificial intelligence exceeds humans in epidemiological job coding

BACKGROUND: Work circumstances can substantially negatively impact health. To explore this, large occupational cohorts of free-text job descriptions are manually coded and linked to exposure. Although several automatic coding tools have been developed, accurate exposure assessment is only feasible with human intervention. METHODS: We developed OPERAS, a customizable decision support system for epidemiological job coding. Using 812,522 entries, we developed and tested classification models for the Professions et Catégories Socioprofessionnelles (PCS)2003, Nomenclature d'Activités Française (NAF)2008, International Standard Classifications of Occupation (ISCO)-88, and ISCO-68. Each code comes with an estimated correctness measure to identify instances potentially requiring expert review. Here, OPERAS' decision support enables an increase in efficiency and accuracy of the coding process through code suggestions. Using the Formaldehyde, Silica, ALOHA, and DOM job-exposure matrices, we assessed the classification models' exposure assessment accuracy. RESULTS: We show that, using expert-coded job descriptions as gold standard, OPERAS realized a 0.66-0.84, 0.62-0.81, 0.60-0.79, and 0.57-0.78 inter-coder reliability (in Cohen's Kappa) on the first, second, third, and fourth coding levels, respectively. These exceed the respective inter-coder reliability of expert coders ranging 0.59-0.76, 0.56-0.71, 0.46-0.63, 0.40-0.56 on the same levels, enabling a 75.0-98.4% exposure assessment accuracy and an estimated 19.7-55.7% minimum workload reduction. CONCLUSIONS: OPERAS secures a high degree of accuracy in occupational classification and exposure assessment of free-text job descriptions, substantially reducing workload. As such, OPERAS significantly outperforms both expert coders and other current coding tools. This enables large-scale, efficient, and effective exposure assessment securing healthy work conditions

Whole Grain Wheat Consumption Affects Postprandial Inflammatory Response in a Randomized Controlled Trial in Overweight and Obese Adults with Mild Hypercholesterolemia in the Graandioos Study

BACKGROUND: Whole grain wheat (WGW) consumption is associated with health benefits in observational studies. However, WGW randomized controlled trial (RCT) studies show mixed effects. OBJECTIVES: The health impact of WGW consumption was investigated by quantification of the body's resilience, which was defined as the "ability to adapt to a standardized challenge." METHODS: A double-blind RCT was performed with overweight and obese (BMI: 25-35 kg/m2) men (n = 19) and postmenopausal women (n = 31) aged 45-70 y, with mildly elevated plasma total cholesterol (>5 mmol/L), who were randomly assigned to either 12-wk WGW (98 g/d) or refined wheat (RW). Before and after the intervention a standardized mixed-meal challenge was performed. Plasma samples were taken after overnight fasting and postprandially (30, 60, 120, and 240 min). Thirty-one biomarkers were quantified focusing on metabolism, liver, cardiovascular health, and inflammation. Linear mixed-models evaluated fasting compared with postprandial intervention effects. Health space models were used to evaluate intervention effects as composite markers representing resilience of inflammation, liver, and metabolism. RESULTS: Postprandial biomarker changes related to liver showed decreased alanine aminotransferase by WGW (P = 0.03) and increased β-hydroxybutyrate (P = 0.001) response in RW. Postprandial changes related to inflammation showed increased C-reactive protein (P = 0.001), IL-6 (P = 0.02), IL-8 (P = 0.007), and decreased IL-1B (P = 0.0002) in RW and decreased C-reactive protein (P < 0.0001), serum amyloid A (P < 0.0001), IL-8 (P = 0.02), and IL-10 (P < 0.0001) in WGW. Health space visualization demonstrated diminished inflammatory (P < 0.01) and liver resilience (P < 0.01) by RW, whereas liver resilience was rejuvenated by WGW (P < 0.05). CONCLUSIONS: Twelve-week 98 g/d WGW consumption can promote liver and inflammatory resilience in overweight and obese subjects with mildly elevated plasma cholesterol. The health space approach appeared appropriate to evaluate intervention effects as composite markers. This trial was registered at www.clinicaltrials.gov as NCT02385149.</p

Towards a Robust Planning of Train Shunting and Servicing

Due to growing demand of sustainable transport, the number of passengers carried by railways is increasing rapidly. Passenger railway operators have to create denser timetables and expand their rolling stock, which leads to logistic challenges on the hubs of the railway network. The hubs consist of train stations and their surrounding shunting yards. Trains that are not operating the timetable are parked, cleaned and maintained on the shunting yards. The planning of all shunting movements and maintenance activities on a hub is still largely done by hand, but with the increasing number of trains this puzzle becomes more and more difficult. In this thesis we focus on developing methods to support and improve the planning of the railway hubs. We present algorithms to generate plans for the integrated shunting, maintenance scheduling and staff assignment problem, and show that these solution methods can solve real-world problem instances of shunting yards and railway hubs in the Netherlands. We also study at the robustness of these plans: can the plan still be implemented properly if small, frequent disruptions such as delays occur? We show that we can create robust plans by guiding the solution methods to plans with beneficial properties such as slack. The planning method presented in this thesis has been tested by the passenger railway company NS at various hubs. The method has proved successful and is now being further developed to support the planners of railway hubs in the Netherlands

Towards a Robust Planning of Train Shunting and Servicing

Due to growing demand of sustainable transport, the number of passengers carried by railways is increasing rapidly. Passenger railway operators have to create denser timetables and expand their rolling stock, which leads to logistic challenges on the hubs of the railway network. The hubs consist of train stations and their surrounding shunting yards. Trains that are not operating the timetable are parked, cleaned and maintained on the shunting yards. The planning of all shunting movements and maintenance activities on a hub is still largely done by hand, but with the increasing number of trains this puzzle becomes more and more difficult. In this thesis we focus on developing methods to support and improve the planning of the railway hubs. We present algorithms to generate plans for the integrated shunting, maintenance scheduling and staff assignment problem, and show that these solution methods can solve real-world problem instances of shunting yards and railway hubs in the Netherlands. We also study at the robustness of these plans: can the plan still be implemented properly if small, frequent disruptions such as delays occur? We show that we can create robust plans by guiding the solution methods to plans with beneficial properties such as slack. The planning method presented in this thesis has been tested by the passenger railway company NS at various hubs. The method has proved successful and is now being further developed to support the planners of railway hubs in the Netherlands

Institutionalization of cross-border regional innovation systems: the role of university institutional entrepreneurs

Cross-border regions are faced with the difficulty that resources for knowledge and innovation may be nearby but difficult to connect to because of the border. Universities could play a supportive role in building innovation environments, facilitating cross-border knowledge exchange. In this research we attempt to understand the systemic roles that universities might play by considering the activities in which they build these cross-border institutional arrangements. We focus upon activities of individual actors, conceptualized as ‘institutional entrepreneurs’. We ask the research question: How can universities through their institutional entrepreneurship activities contribute to the institutionalization of cross-border innovation environments that facilitate cross-border resource access for innovating actors? We address it by developing a conceptual framework for how these institutional entrepreneurs may operate, and identify three repertoires of contributions. We then explore how university actors in a specific cross-border region have built linkages that have acquired a degree of permanence

Border blocking effects in collaborative firm innovation

Border regions are not often associated with innovation and economic prosperity. And even when they are prosperous, cross-border interaction is still mostly limited. The opening up of borders in Europe has presented new opportunities for firms located in these border regions to co-operate for innovation and knowledge to flow across borders. Despite the reduction of the importance of borders, firms seeking to access cross-border knowledge resources need still to ‘cross’ the border and address the various effects it brings. This paper therefore asks the question of how the presence of a border affects the processes by which firms attempt to build up productive co-operations for innovation. We use a heuristic of collaborative innovation across borders as building up through four sequential cooperation stages, and each of these different stages is susceptible to different kinds of border effects. Using a case study of firms co-operating across the Dutch-Flemish border, we empirically explore these border crossing processes in order to shed further light on how border processes play out

Innovation and SMEs in Interreg policy: too early to move beyond bike lanes?

Since 1989 the European Commission’s policy on border regions has slowly shifted focus. Current Interreg policy is increasingly focused upon innovation and cooperation between SMEs. In this paper we question whether this emphasis on firms and innovation neglects the build-up of other kinds of activities and institutions antecedent to effective firm innovation cooperation. We argue that antecedent developments should occur prior to stimulating innovation cooperation between firms, highlighting that building effective environments for regional innovation in cross-border regions encompasses four qualitatively different micro scale phases of development, each requiring qualitatively different policy measures. This four-phase model is applied to a case study of a Dutch-Flemish Interreg programme, using documentary material, a policy-maker survey and a documentary analysis of funded projects to explore incoherences between strategy and reality. We highlight a gap between the strategy’s strong ex ante focus upon innovation, policy-maker perceptions of necessary improvements, and the projects selected for funding