Collision-Free Intersection Crossing of Mobile Robots Using Decentralized Navigation Functions on Predefined Paths

This paper deals with the coordination of a group of mobile robots at an intersection. It focusses on decentralized navigation functions (DNFs) to achieve efficient traffic control. The main challenge is to define virtual potentials, which are used by decentralized navigation functions, such that traffic is both fluent and safe, while taking into account real-world limitations like acceleration, braking and speed limits. Our method consists in defining the navigation function with respect to the desired acceleration profile and is accompanied by a set of visibility conditions that increase the capacity of the intersection in terms of vehicle throughput. Priority conditions have been used to both avoid blockades of robots and to save energy by assigning higher priorities to robots with higher inertias

How do African SMEs respond to climate risks? Evidence from Kenya and Senegal

This paper investigates to what extent and how small and medium-sized enterprises (SMEs) in poor countries are adapting to climate risks using data from 325 SMEs in the semi-arid regions of Kenya and Senegal. There is a clear role for public policy in facilitating good adaptation. The ability of firms to respond to climate risks depends on factors that can be shaped through policy intervention. Findings show that financial barriers are a key reason why firms resort to reactive coping mechanisms, while general business support, access to information technology and adaptation assistance encourages sustainable adaptation responses.UK Government’s Department for International Development (DfID)Financial support from the Grantham Foundation for the Protection of the Environment, and the UK Economic and Social Research Council (ESRC) through the Centre for Climate Change Economics and Polic

Das Triftprojekt : ein Überblick zu Projekt, Ökologie und Partizipation

Mit der Realisierung des Triftprojekts kann ein wesentlicher Beitrag zur erfolgreichen Umsetzung der schweizerischen Energiewende geleistet werden. Neben einer Erhöhung der Energieproduktion um 145 GWh/a kann künftig die Flexibilität der Stromproduktion erhöht und insbesondere ein Grossteil der Stromproduktion im Winter erfolgen. Allerdings sind mit dieser energiepolitischen Verbesserung sowohl gewässerökologische als auch terrestrische Beeinträchtigungen verbunden. Die umfangreichen und sehr detaillierten ökologischen Untersuchungen bildeten eine hervorragende Ausgangsbasis zur Beurteilung des Projekts und eine sachliche Diskussion. Im Rahmen eines gut strukturierten Begleitprozesses hatten alle relevanten Stakeholder die Möglichkeit, sich aktiv in die Diskussionen und Lösungsfindung einzubringen. Die Diskussionen im Begleitprozess verliefen sehr offen und lösungsorientiert. Mit zwei von allen Seiten anerkannten Bewertungsmethoden wurden die ökologischen Beeinträchtigungen und die Aufwertungsmassnahmen sowohl für aquatische als auch für terrestrische Lebensräume objektiv bilanziert. Nach rund drei Jahren Verhandlungen wurde schliesslich für alle relevanten ökologischen und technischen Aspekte eine Lösung gefunden und wurden die Konzessionsunterlagen im Herbst 2017 eingereicht

Location Prediction over Sparse User Mobility Traces Using RNNs: Flashback in Hidden States!

Location prediction is a key problem in human mobility modeling, which predicts a user's next location based on historical user mobility traces. As a sequential prediction problem by nature, it has been recently studied using Recurrent Neural Networks (RNNs). Due to the sparsity of user mobility traces, existing techniques strive to improve RNNs by considering spatiotemporal contexts. The most adopted scheme is to incorporate spatiotemporal factors into the recurrent hidden state passing process of RNNs using context-parameterized transition matrices or gates. However, such a scheme oversimplifies the temporal periodicity and spatial regularity of user mobility, and thus cannot fully benefit from rich historical spatiotemporal contexts encoded in user mobility traces. Against this background, we propose Flashback, a general RNN architecture designed for modeling sparse user mobility traces by doing flashbacks on hidden states in RNNs. Specifically, Flashback explicitly uses spatiotemporal contexts to search past hidden states with high predictive power (i.e., historical hidden states sharing similar contexts as the current one) for location prediction, which can then directly benefit from rich spatiotemporal contexts. Our extensive evaluation compares Flashback against a sizable collection of state-of-the-art techniques on two real-world LBSN datasets. Results show that Flashback consistently and significantly outperforms state-of-the-art RNNs involving spatiotemporal factors by 15.9% to 27.6% in the next location prediction task

Regulating net zero: from groundswell to ground rules

Following a groundswell of voluntary net-zero targets by companies, regulators are increasingly introducing mandatory rules. If governments can overcome the barriers to rigour, coherence and fairness, such mandatory ‘ground rules’ have the potential to overcome the obstructionism that holds back a just climate transition

Impact of preoperative systemic immune-inflammation Index on oncologic outcomes in bladder cancer patients treated with radical cystectomy

PURPOSE To investigate the predictive and prognostic value of the preoperative systemic immune-inflammation index (SII) in patients undergoing radical cystectomy (RC) for clinically non-metastatic urothelial cancer of the bladder (UCB). METHODS Overall, 4,335 patients were included, and the cohort was stratified in two groups according to SII using an optimal cut-off determined by the Youden index. Uni- and multivariable logistic and Cox regression analyses were performed, and the discriminatory ability by adding SII to a reference model based on available clinicopathologic variables was assessed by area under receiver operating characteristics curves (AUC) and concordance-indices. The additional clinical net-benefit was assessed using decision curve analysis (DCA). RESULTS High SII was observed in 1879 (43%) patients. On multivariable preoperative logistic regression, high SII was associated with lymph node involvement (LNI; P = 0.004), pT3/4 disease (P <0.001), and non-organ confined disease (NOCD; P <0.001) with improvement of AUCs for predicting LNI (P = 0.01) and pT3/4 disease (P = 0.01). On multivariable Cox regression including preoperative available clinicopathologic values, high SII was associated with recurrence-free survival (P = 0.028), cancer-specific survival (P = 0.005), and overall survival (P = 0.006), without improvement of concordance-indices. On DCAs, the inclusion of SII did not meaningfully improve the net-benefit for clinical decision-making in all models. CONCLUSION High preoperative SII is independently associated with pathologic features of aggressive disease and worse survival outcomes. However, it did not improve the discriminatory margin of a prediction model beyond established clinicopathologic features and failed to add clinical benefit for decision making. The implementation of SII as a part of a panel of biomarkers in future studies might improve decision-making

Comparative outcomes of primary versus recurrent high-risk nonmuscle-invasive and primary versus secondary muscle-invasive bladder cancer after radical cystectomy : results from a retrospective multicenter study

BACKGROUND: Radical cystectomy (RC) is indicated in primary or secondary muscle-invasive bladder cancer (primMIBC, secMIBC) and in primary or recurrent high- or very high-risk non–muscle-invasive bladder cancer (primHR-NMIBC, recHR-NMIBC). The optimal timing for RC along the disease spectrum of nonmetastatic urothelial carcinoma remains unclear. OBJECTIVE: To compare outcomes after RC between patients with primHR-NMIBC, recHR-NMIBC, primMIBC, and secMIBC. DESIGN, SETTING, AND PARTICIPANTS: This retrospective, multicenter study included patients with clinically nonmetastatic bladder cancer (BC) treated with RC. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We assessed oncological outcomes for patients who underwent RC according to the natural history of their BC. primHR-NMIBC and primMIBC were defined as no prior history of BC, and recHR-NMIBC and secMIBC as previously treated NMIBC that recurred or progressed to MIBC, respectively. Log-rank analysis was used to compare survival outcomes, and univariable and multivariable Cox and logistic regression analyses were used to identify predictors for survival. RESULTS AND LIMITATIONS: Among the 908 patients included, 211 (23%) had primHR-NMIBC, 125 (14%) had recHR-NMIBC, 404 (44%) had primMIBC, and 168 (19%) had secMIBC. Lymph node involvement and pathological upstaging were more frequent in the secMIBC group than in the other groups (p < 0.001). The median follow-up was 37 mo. The 5-year recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS) were 77.9%, 83.2%, and 72.7% in primHR-NMIBC, 60.0%, 59%, and 48.9% in recHR-NMIBC, 60.9%, 64.5%, and 54.8% in primMIBC, and 41.3%, 46.5%, and 39% in secMIBC, respectively, with statistically significant differences across all survival outcomes except between recHR-NMIBC and primMIBC. On multivariable Cox regression, recHR-NMIBC was independently associated with shorter RFS (hazard ratio [HR] 1.64; p = 0.03), CSS (HR 1.79; p = 0.01), and OS (HR 1.45; p = 0.03), and secMIBC was associated with shorter CSS (HR 1.77; p = 0.01) and OS (HR 1.57; p = 0.006). Limitations include the biases inherent to the retrospective study design. CONCLUSIONS: Patients with recHR-NMIBC and primHR-MIBC had similar survival outcomes, while those with sec-MIBC had the worst outcomes. Therefore, early radical intervention may be indicated in selected patients, and potentially neoadjuvant systemic therapies in some patients with recHR-NMIBC. PATIENT SUMMARY: We compared cancer outcomes in different bladder cancer scenarios in a large, multinational series of patients who underwent removal of the bladder with curative intent. We found that patients who experienced recurrence of non–muscle-invasive bladder cancer (NMIBC) had similar survival outcomes to those with initial muscle-invasive bladder cancer (MIBC), while patients who experienced progression of NMIBC to MIBC had the worst outcomes. Selected patients with non–muscle-invasive disease may benefit from early radical surgery or from perioperative chemotherapy or immunotherapy