Improving Operational Efficiency In EV Ridepooling Fleets By Predictive Exploitation of Idle Times

In ridepooling systems with electric fleets, charging is a complex decision-making process. Most electric vehicle (EV) taxi services require drivers to make egoistic decisions, leading to decentralized ad-hoc charging strategies. The current state of the mobility system is often lacking or not shared between vehicles, making it impossible to make a system-optimal decision. Most existing approaches do not combine time, location and duration into a comprehensive control algorithm or are unsuitable for real-time operation. We therefore present a real-time predictive charging method for ridepooling services with a single operator, called Idle Time Exploitation (ITX), which predicts the periods where vehicles are idle and exploits these periods to harvest energy. It relies on Graph Convolutional Networks and a linear assignment algorithm to devise an optimal pairing of vehicles and charging stations, in pursuance of maximizing the exploited idle time. We evaluated our approach through extensive simulation studies on real-world datasets from New York City. The results demonstrate that ITX outperforms all baseline methods by at least 5% (equivalent to $70,000 for a 6,000 vehicle operation) per week in terms of a monetary reward function which was modeled to replicate the profitability of a real-world ridepooling system. Moreover, ITX can reduce delays by at least 4.68% in comparison with baseline methods and generally increase passenger comfort by facilitating a better spread of customers across the fleet. Our results also demonstrate that ITX enables vehicles to harvest energy during the day, stabilizing battery levels and increasing resilience to unexpected surges in demand. Lastly, compared to the best-performing baseline strategy, peak loads are reduced by 17.39% which benefits grid operators and paves the way for more sustainable use of the electrical grid

Lifetime Assessment of Load-Bearing Polymer Glasses: The Influence of Physical Ageing

The timescale at which ductile failure occurs in loaded glassy polymers can be successfully predicted using the engineering approach presented in a previous publication. In this paper the influence of progressive physical ageing on the plastic deformation behaviour of unplasticised poly(vinyl chloride) (uPVC) is characterised and incorporated in the existing approach. With the modification it is possible to quantitatively predict long-term failures which show a so-called endurance limit. The predictions are compared with failure data of uPVC specimens which were subjected to constant or dynamic loads. In dynamic loading conditions a second type of failure mode was observed: fatigue crack growth. A brief study on the influence of the frequency and stress ratio of the applied stress signal shows that crack growth failure is not expected to occur within experimentally reasonable timescales for constant loading conditions

Ontwerpregels voor kruispunten in stedelijke netwerken (Design rules for junctions in urban networks).

Veel ontwerprichtlijnen voor wegen bevatten richtlijnen of aanbevelingen voor het ontwerpen van kruispunten in stedelijke gebieden. Daarbij gaat het in eerste instantie om het bepalen van het kruispunttype en vervolgens om de specifieke inrichting van bijvoorbeeld de (opstel)stroken, instellingen voor een eventuele verkeersregelinstallatie en de voorrangsregeling voor fietsers en/of voetgangers. De richtlijnen bevatten vaak een set van regels welke gebruikt kunnen worden om te bepalen welk kruispuntontwerp, of welk kruispunttype, in een specifieke situatie het beste is. Wat het beste is en dus welke criteria daarbij van belang zijn, kan daarbij variëren. De set van regels is doorgaans gebaseerd op vuistregels en/of eenvoudige (hiërarchische) beslisschema’s met als invoer de intensiteiten voor alle richtingen op het kruispunt. Er wordt gewerkt met criteria voor verkeersveiligheid en verkeersafwikkeling en in beperkte mate met criteria ten aanzien van milieu. De huidige ontwerpregels ontberen eenduidigheid. In de criteria worden meerdere vuistregels en rekenmethoden en criteria voor meerdere beleidsdoelen door elkaar gebruikt. Daarnaast wordt vaak een beperkt aantal ontwerpvarianten getoetst, waardoor de kans aanwezig is dat de ‘beste’ oplossing niet gevonden wordt, omdat deze variant niet is bedacht. Verder is het de vraag wat voor effect het consequent doorvoeren van lokale ontwerpregels heeft op de netwerkprestaties voor verschillende beleids(doelen). Wellicht is het beter om op bepaalde locaties te kiezen voor een ‘sub-optimale’ doserende kruispuntvorm, ten behoeve van een betere prestatie op netwerkniveau. Er is behoefte aan ontwerpregels voor kruispunten in stedelijke netwerken, waarmee op een systematische wijze een afweging gemaakt kan worden tussen het belang of gewicht van verschillende beleidsdoelen op zowel lokaal als netwerkniveau. Hierbij gaat het met name om beleidsdoelen die bijdragen aan het minimaliseren van de negatieve effecten van verkeer, zoals congestie, verkeersonveiligheid, uitstoot van schadelijke stoffen en geluidhinder. In deze paper wordt een onderzoeksopzet gepresenteerd waarmee deze behoefte wordt ingevuld en dus ontwerpregels bepaald, geanalyseerd en toegepast kunnen worden. Dit gebeurt op basis van modelsimulaties en de regels worden uiteindelijk toegepast in een beslissingsondersteunend instrument. De resultaten van het onderzoek zijn naast de nieuwe ontwerpregels, nieuwe kennis of inzichten in de netwerkeffecten van ontwerpregels voor meerdere doelen, een instrument om de regels te bepalen en een beslissingsondersteunend instrument voor het toepassen van de regels in beleidssituaties. De onderzoeksopzet wordt geïllustreerd aan de hand van een eerste uitwerking op basis van een theoretisch voorbeeld

Long-term cardiac follow-up of athletes infected with SARS-CoV-2 after resumption of elite-level sports

OBJECTIVE: Longitudinal consequences and potential interactions of COVID-19 and elite-level sports and exercise are unclear. Therefore, we determined the long-term detrimental cardiac effects of the interaction between SARS-CoV-2 infection and the highest level of sports and exercise.METHODS: This prospective controlled study included elite athletes from the Evaluation of Lifetime participation in Intensive Top-level sports and Exercise cohort. Athletes infected with SARS-CoV-2were offered structured, additional cardiovascular screenings, including cardiovascular MRI (CMR). We compared ventricular volumes and function, late gadolinium enhancement (LGE) and T1 relaxation times, between infected and non-infected elite athletes, and collected follow-up data on cardiac adverse events, ventricular arrhythmia burden and the cessation of sports careers.RESULTS: We included 259 elite athletes (mean age 26±5 years; 40% women), of whom 123 were infected (9% cardiovascular symptoms) and 136 were controls. We found no differences in function and volumetric CMR parameters. Four infected athletes (3%) demonstrated LGE (one reversible), compared with none of the controls. During the 26.7 (±5.8) months follow-up, all four athletes resumed elite-level sports, without an increase in ventricular arrhythmias or adverse cardiac remodelling. None of the infected athletes reported new cardiac symptoms or events. The majority (n=118; 96%) still participated in elite-level sports; no sports careers were terminated due to SARS-CoV-2.CONCLUSIONS: This prospective study demonstrates the safety of resuming elite-level sports after SARS-CoV-2 infection. The medium-term risks associated with SARS-CoV-2 infection and elite-level sports appear low, as the resumption of elite sports did not lead to detrimental cardiac effects or increases in clinical events, even in the four elite athletes with SARS-CoV-2 associated myocardial involvement.</p

Preoperative chemoradiotherapy but not chemotherapy is associated with reduced risk of postoperative pancreatic fistula after pancreatoduodenectomy for pancreatic ductal adenocarcinoma:a nationwide analysis

Background: Postoperative pancreatic fistula remains the leading cause of significant morbidity after pancreatoduodenectomy for pancreatic ductal adenocarcinoma. Preoperative chemoradiotherapy has been described to reduce the risk of postoperative pancreatic fistula, but randomized trials on neoadjuvant treatment in pancreatic ductal adenocarcinoma focus increasingly on preoperative chemotherapy rather than preoperative chemoradiotherapy. This study aimed to investigate the impact of preoperative chemotherapy and preoperative chemoradiotherapy on postoperative pancreatic fistula and other pancreatic-specific surgery related complications on a nationwide level. Methods: All patients after pancreatoduodenectomy for pancreatic ductal adenocarcinoma were included in the mandatory nationwide prospective Dutch Pancreatic Cancer Audit (2014–2020). Baseline and treatment characteristics were compared between immediate surgery, preoperative chemotherapy, and preoperative chemoradiotherapy. The relationship between preoperative chemotherapy, chemoradiotherapy, and clinically relevant postoperative pancreatic fistula (International Study Group of Pancreatic Surgery grade B/C) was investigated using multivariable logistic regression analyses. Results: Overall, 2,019 patients after pancreatoduodenectomy for pancreatic ductal adenocarcinoma were included, of whom 1,678 underwent immediate surgery (83.1%), 192 (9.5%) received preoperative chemotherapy, and 149 (7.4%) received preoperative chemoradiotherapy. Postoperative pancreatic fistula occurred in 8.3% of patients after immediate surgery, 4.2% after preoperative chemotherapy, and 2.0% after preoperative chemoradiotherapy (P = .004). In multivariable analysis, the use of preoperative chemoradiotherapy was associated with reduced risk of postoperative pancreatic fistula (odds ratio, 0.21; 95% confidence interval, 0.03–0.69; P = .033) compared with immediate surgery, whereas preoperative chemotherapy was not (odds ratio, 0.59; 95% confidence interval, 0.25–1.25; P = .199). Intraoperatively hard, or fibrotic pancreatic texture was most frequently observed after preoperative chemoradiotherapy (53% immediate surgery, 62% preoperative chemotherapy, 77% preoperative chemoradiotherapy, P &lt; .001). Conclusion: This nationwide analysis demonstrated that in patients undergoing pancreatoduodenectomy for pancreatic ductal adenocarcinoma, only preoperative chemoradiotherapy, but not preoperative chemotherapy, was associated with a reduced risk of postoperative pancreatic fistula.</p

Preoperative chemoradiotherapy but not chemotherapy is associated with reduced risk of postoperative pancreatic fistula after pancreatoduodenectomy for pancreatic ductal adenocarcinoma:a nationwide analysis

Background: Postoperative pancreatic fistula remains the leading cause of significant morbidity after pancreatoduodenectomy for pancreatic ductal adenocarcinoma. Preoperative chemoradiotherapy has been described to reduce the risk of postoperative pancreatic fistula, but randomized trials on neoadjuvant treatment in pancreatic ductal adenocarcinoma focus increasingly on preoperative chemotherapy rather than preoperative chemoradiotherapy. This study aimed to investigate the impact of preoperative chemotherapy and preoperative chemoradiotherapy on postoperative pancreatic fistula and other pancreatic-specific surgery related complications on a nationwide level. Methods: All patients after pancreatoduodenectomy for pancreatic ductal adenocarcinoma were included in the mandatory nationwide prospective Dutch Pancreatic Cancer Audit (2014–2020). Baseline and treatment characteristics were compared between immediate surgery, preoperative chemotherapy, and preoperative chemoradiotherapy. The relationship between preoperative chemotherapy, chemoradiotherapy, and clinically relevant postoperative pancreatic fistula (International Study Group of Pancreatic Surgery grade B/C) was investigated using multivariable logistic regression analyses. Results: Overall, 2,019 patients after pancreatoduodenectomy for pancreatic ductal adenocarcinoma were included, of whom 1,678 underwent immediate surgery (83.1%), 192 (9.5%) received preoperative chemotherapy, and 149 (7.4%) received preoperative chemoradiotherapy. Postoperative pancreatic fistula occurred in 8.3% of patients after immediate surgery, 4.2% after preoperative chemotherapy, and 2.0% after preoperative chemoradiotherapy (P = .004). In multivariable analysis, the use of preoperative chemoradiotherapy was associated with reduced risk of postoperative pancreatic fistula (odds ratio, 0.21; 95% confidence interval, 0.03–0.69; P = .033) compared with immediate surgery, whereas preoperative chemotherapy was not (odds ratio, 0.59; 95% confidence interval, 0.25–1.25; P = .199). Intraoperatively hard, or fibrotic pancreatic texture was most frequently observed after preoperative chemoradiotherapy (53% immediate surgery, 62% preoperative chemotherapy, 77% preoperative chemoradiotherapy, P &lt; .001). Conclusion: This nationwide analysis demonstrated that in patients undergoing pancreatoduodenectomy for pancreatic ductal adenocarcinoma, only preoperative chemoradiotherapy, but not preoperative chemotherapy, was associated with a reduced risk of postoperative pancreatic fistula.</p