100 research outputs found
Passengers, Information, and Disruptions
Passengers traveling in public transport generate a detailed digital track record of their journey through using automated fare collection systems and carrying mobile devices. This information on passenger behavior has only recently become available to public transport operators. This thesis addresses the question how this new information can be used to improve passenger service in case of disruptions in public transportation.
Major disruptions cause the current logistical schedule of the operator to be infeasible. Adjusting this schedule to the disruption is a complicated planning problem. Passengers will adjust their journeys to the new schedule, and may need to adjust their route choice due to the route choice of other passengers in case of capacity shortages. Therefore the passenger service results from a complex interaction between passengers themselves, and between passengers and the schedule.
This thesis proposes new models for improving passenger service in case of major disruptions by adjusting the schedule while anticipating passenger’s reactions, and also by supporting passengers during disruptions through the provision of route advice. This research is combined with a study on passenger behavior based on the new data sources. The models are evaluated using data and case studies of the passenger rail network of Netherlands Railways and the urban rail network of the Massachusetts Bay Transportation Authority. It was found that indeed this new information, together with the option to provide route advice to passengers, could significantly improve service during major disruptions
Recognizing demand patterns from smart card data for agent-based micro-simulation of public transport
Shuttle Planning for Link Closures in Urban Public Transport Networks
Urban Public Transport systems must periodically close certain links for main- tenance, which can have significant effects on the service provided to passengers. In practice, the effects of closures are mitigated by replacing the link with a simple shuttle service. However, alternative shuttle services could reduce inconvenience at lower op- erating cost. This paper proposes a model to select shuttle lines and frequencies under budget constraints. A new formulation is proposed that allows a minimal frequency restriction on any line that is operated, and minimizes passenger inconvenience cost, including transfers and frequency-dependent waiting time. This model is applied to a shuttle design problem based on a real world case study of the MBTA network of Boston (USA). The results show that additional shuttle routes can reduce passenger delay in comparison to the standard industry practice, while also distributing delay more equally over passengers, at the same operating budget. The results are robust under different assumptions about passenger route choice behavior. Computational experiments show that the proposed formulation, coupled with a preprocessing step, can be solved faster than prior formulations
Increase of Simultaneous Soybean Failures Due To Climate Change
While soybeans are among the most consumed crops in the world, most of its production lies in the US, Brazil, and Argentina. The concentration of soybean growing regions in the Americas renders the supply chain vulnerable to regional disruptions. In 2012, anomalous hot and dry conditions occurring simultaneously in these regions led to low soybean yields, which drove global soybean prices to all-time records. In this study, we explore climate change impacts on simultaneous extreme crop failures as the one from 2012. We develop a hybrid model, coupling a process-based crop model with a machine learning model, to improve the simulation of soybean production. We assess the frequency and magnitude of events with similar or higher impacts than 2012 under different future scenarios, evaluating anomalies both with respect to present day and future conditions to disentangle the impacts of (changing) climate variability from the long-term mean trends. We find long-term trends in mean climate increase the frequency of 2012 analogs by 11–16 times and the magnitude by 4–15% compared to changes in climate variability only depending on the global climate scenario. Conversely, anomalies like the 2012 event due to changes in climate variability show an increase in frequency in each country individually, but not simultaneously across the Americas. We deduce that adaptation of the crop production practice to the long-term mean trends of climate change may considerably reduce the future risk of simultaneous soybean losses across the Americas
Optimal clinical management of children receiving ketogenic parenteral nutrition: a clinical practice guide
AIM: To give evidence-based recommendations on the application of ketogenic diet parenteral nutrition (KD-PN) in emergency situations. METHOD: An international group of experts (n=14) researched the literature and distributed a survey among 150 expert centers. International accepted guidelines (European Society for Clinical Nutrition and Metabolism/European Society for Paediatric Gastroenterology Hepatology and Nutrition and the American Society for Parenteral and Enteral Nutrition) and handbooks for parenteral nutrition were considered general standards of care. RESULTS: In the literature, we identified 35 reports of patients treated by KD-PN. International guidelines and handbooks provided some conflicting information. Twenty-four expert teams from nine countries responded to the survey, reflecting the limited clinical experience. INTERPRETATION: This paper highlights 23 consensus-based recommendations for safe and effective KD-PN (e.g. diet initiation, calculation, application, monitoring, and evaluation) based on the best evidence available and expert opinions. WHAT THIS PAPER ADDS: In acute settings, ketogenic diet therapy (KDT) can be administered parenterally. Parenteral administration of KDT should be started only at the intensive care unit. Initiate ketogenic parenteral nutrition stepwise to the highest ratio possible with the lowest level of complications. Evaluate the risk-benefit ratio of parenteral administration continuously. Restart enteral feeding as soon as appropriate
The PRO-RCC study:a long-term PROspective Renal Cell Carcinoma cohort in the Netherlands, providing an infrastructure for ‘Trial within Cohorts’ study designs
BACKGROUND: Ongoing research in the field of both localized, locally advanced and metastatic renal cell carcinoma has resulted in the availability of multiple treatment options. Hence, many questions are still unanswered and await further research. A nationwide collaborative registry allows to collect corresponding data. For this purpose, the Dutch PROspective Renal Cell Carcinoma cohort (PRO-RCC) has been founded, for the prospective collection of long-term clinical data, patient reported outcome measures (PROMs) and patient reported experience measures (PREMs).METHODS: PRO-RCC is designed as a multicenter cohort for all Dutch patients with renal cell carcinoma (RCC). Recruitment will start in the Netherlands in 2023. Importantly, participants may also consent to participation in a 'Trial within cohorts' studies (TwiCs). The TwiCs design provides a method to perform (randomized) interventional studies within the registry. The clinical data collection is embedded in the Netherlands Cancer Registry (NCR). Next to the standardly available data on RCC, additional clinical data will be collected. PROMS entail Health-Related Quality of Life (HRQoL), symptom monitoring with optional ecological momentary assessment (EMA) of pain and fatigue, and optional return to work- and/or nutrition questionnaires. PREMS entail satisfaction with care. Both PROMS and PREMS are collected through the PROFILES registry and are accessible for the patient and the treating physician.TRIAL REGISTRATION: Ethical board approval has been obtained (2021_218) and the study has been registered at ClinicalTrials.gov (NCT05326620).DISCUSSION: PRO-RCC is a nationwide long-term cohort for the collection of real-world clinical data, PROMS and PREMS. By facilitating an infrastructure for the collection of prospective data on RCC, PRO-RCC will contribute to observational research in a real-world study population and prove effectiveness in daily clinical practice. The infrastructure of this cohort also enables that interventional studies can be conducted with the TwiCs design, without the disadvantages of classic RCTs such as slow patient accrual and risk of dropping out after randomization.</p
Optimal clinical management of children receiving ketogenic parenteral nutrition: a clinical practice guide
AIM To give evidence-based recommendations on the application of ketogenic diet
parenteral nutrition (KD-PN) in emergency situations.
METHOD An international group of experts (n=14) researched the literature and distributed a
survey among 150 expert centers. International accepted guidelines (European Society for
Clinical Nutrition and Metabolism/European Society for Paediatric Gastroenterology
Hepatology and Nutrition and the American Society for Parenteral and Enteral Nutrition) and
handbooks for parenteral nutrition were considered general standards of care.
RESULTS In the literature, we identified 35 reports of patients treated by KD-PN. International
guidelines and handbooks provided some conflicting information. Twenty-four expert teams
from nine countries responded to the survey, reflecting the limited clinical experience.
INTERPRETATION This paper highlights 23 consensus-based recommendations for safe and
effective KD-PN (e.g. diet initiation, calculation, application, monitoring, and evaluation)
based on the best evidence available and expert opinions
Tales of future weather
Society is vulnerable to extreme weather events and, by extension, to human impacts on future events. As climate changes weather patterns will change. The search is on for more effective methodologies to aid decision-makers both in mitigation to avoid climate change and in adaptation to changes. The traditional approach uses ensembles of climate model simulations, statistical bias correction, downscaling to the spatial and temporal scales relevant to decision-makers, and then translation into quantities of interest. The veracity of this approach cannot be tested, and it faces in-principle challenges. Alternatively, numerical weather prediction models in a hypothetical climate setting can provide tailored narratives for high-resolution simulations of high-impact weather in a future climate. This 'tales of future weather' approach will aid in the interpretation of lower-resolution simulations. Arguably, it potentially provides complementary, more realistic and more physically consistent pictures of what future weather might look like
Aandacht voor veiligheid
De komende decennia worden er tussen de 500.000 en 1.500.000 woningen gebouwd waarvan een groot deel in laag Nederland. Deze studie laat zien dat door deze woningen overstromingsbestendig te bouwen schadereductie mogelijk is. Het schaderisico wordt dan nog eens een factor 2 minder als naast een Business as Usual variant nieuwbouwwoningen worden opgehoogd tot +5 m NAP. De kosten van opgehoogde nieuwbouwhuizen zijn hoger en variëren tussen de 0,4 en 1.7 miljard euro/jaar, hetgeen overeenkomt met 0,1-0,5% van het BNP. Dijkversterking levert de hoogste reductie op in het schaderisico bij de gehanteerde scenario’s. Gevolgbeperkende maatregelen in de ruimtelijk ordening als additionele oplossingsrichting zijn echter goed mogelijk als er ook een economische perspectief is bijvoorbeeld door middel van multifunctioneel ruimtegebruik
- …